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A New Approach to the Khandhas – How We Experience the World

26 Feb


‘What is this world condition?

Body is the world condition.

And with body and form go feeling, perception, consciousness, and all the activities throughout the world.

The arising of form and the ceasing of form – everything that has been heard, sensed, and known, sought after and reached by the mind – all this is the embodied world, to be penetrated and realized.’ Samyutta Nikaya

‘The ‘world’ of experience is not given in experience: it is constructed by thought from the data of sense.’I. Lewis1


For us to understand the profundity of the Buddha’s teachings, we must first turn to an examination of the khandhas. According to the Wisdom Library2, the khandhas (Pali) (Sanskrit: skandhas) or Five Aggregates are the five components of a being which come together at birth and separate at death:

(1) Matter or form (rupa) – external and internal matter. Externally, rupa is the physical world. Internally, rupa includes the material body and the physical sense organs, i.e. eye, ear, nose, tongue, and body;

(2) Sensation or feeling (vedana) – the feeling in reception of physical things by the senses through the mind;

(3) Perception and/or cognition (sanna) – the functioning of mind in distinguishing appearances;

(4) Volition or mental formation (sankara) – habitual action, i.e. a conditioned response to the object of experience, whether it is good or evil, whether you like or dislike it;

(5) Consciousness (vinnana) – the mental faculty engaged in perception, cognition, and experience.



Figure  2

The Traditional Interpretation of Khandha


Khandha is most frequently translated into English as ‘aggregate.’ Before the Buddha’s particular use of the word, the word khandha had very common meanings: a khandha could be a pile, a bundle, a heap, a mass. Inaccurately, this image of a ‘pile’ has continued to be used in describing the Buddha’s use of the word. For example, as Thanissaro Bhikkhu traditionally uses the term, ‘The five khandhas are bundles or piles of form, feeling, perception, fabrications, and consciousness. […] The common and explicit image is of the khandhas as burdensome.’ (SN 22.22)3

Or as C.A.F. Rhys Davids wrote:

‘And the Khandhas stand exposed as the vehicles of pain and misery, and as “a burden” taken up ever again by craving ever-reborn – craving of sense-desires, craving for rebirth.’4

Extended Interpretation of Khandhas


Sue Hamilton, in her book Early Buddhism: A New Approach: The I of the Beholder, makes a significant extension of reference from the above traditional doctrine of the khandhas as five individual, separate, burdensome aggregates or ‘piles.’ She cogently argues that, in his first sermon and after, the Buddha always referred to the khandhas as a collective, unified unit, and only as a unified unit can one best understand the Buddha’s perspective regarding their function. In their collective function, the khandhas refer to the body as a living organism that provides the basis for our ability to know anything.

This important formulation of the khandhas as an integrated organic whole, highlights the reality that it isn’t possible for us to separate ourselves from our experience, nor is it possible to know anything other than by the khandhas. There is not only no separation between our self and our experience; there is also no separation between mind and body. The human ability to conceptualize relies on the sensory data that are filtered through the collective unit of khandhas. From this perspective, the khandhas are not a ‘burden’ and cannot be separated or jettisoned from our experience – nor should they be.

They are our experience. We know the world through the khandhas. The khandhas must be understood not as five separate ‘heaps’ of bodily material but as a cohesive, living physical apparatus, an apparatus whose main operating processes are centered on the survival of the organism and the functioning of our cognitions.

So we come to understand that our senses are not ‘windows on the world’ and what we see isn’t actually what’s out there but instead an ‘informed guess’. Our brain constructs a reality of the external world based on what evolution has developed as a capacity of cognitive construction of what we need to know for our survival.

Khandas as a Collective, Unified Unit


This crucial point of understanding the khandhas as a collective, unified, organic unit and not five separately functioning bases is similar to what Marek McGann explains as the enactive cognitive position regarding our cognitions.5 McGann notes that, while individual sensory organs may be vital, no perception depends on, or can be explained by, the input of a specific organ alone. All perception is inherently multi-modal. Modalities are not atomic in nature; rather, they are a product of a dynamic process which involves an embodied agent (with goals and sensitivities) and a world. Any aspect of a person’s awareness during a particular action will have to be described and interpreted in light of the rest of the system during that same activity. In other words, the khandhas, or body as a living organism, is an organization of interacting modalities.

With Hamilton’s extension of understanding, we analyze the khandhas as interacting modalities of a unified organization. This leads us to a very different analysis of the nexus of interactions of the khandhas, the cognitive apparatus through which we construct our ‘world,’ so it makes sense to us. Ultimately, instead of the traditional analysis focusing on the impermanence of each separate ‘heap’ or khandha as the root of suffering, we understand on a more radical and profound level that the sources of our suffering are the illusory cognitive constructions of ‘self’ and ‘world’ with their accompanying cravings. The result is that, with Enlightenment, one ceases to grasp at the object and subject of experience. Enlightenment results from insight into, and the dis-identification of, the thoughts and the conceptual constructions and projections that provide the foundation for our pre-enlightened cognitions. This dis-identification transforms our basic and mundane mode of cognition into ‘pure experience’ (emptiness), which is defined as non-conceptual and devoid of interpretive overlay. Much of this book explores the implications of this extended analysis.

The Explanatory Analysis of the Five


The five khandhas are the body, consciousness, sensations or feelings, apperception, and volitional activities. The body is significant as a khandha not as simply a ‘pile’ of matter, but as the living organism which is the origin of one’s ‘experience’ – the locus of the senses through which we experience the world. In Buddhism there are six senses of the body: seeing, hearing, smelling, tasting, touching, and ‘mind.’ While the first five are familiar to us, we usually do not consider mind a sixth sense. As Hamilton states, ‘[…] in the early Buddhist teachings (mind) is the faculty, or sense, which filters and collates all sensory data so it can actually make sense to us.’6 In the Buddha’s teachings, it is mind that mediates everything the other senses collect, that makes sense of the huge volume of information that arises with the interaction between our sense organs and sense datum. Mind is not a permanent substance; it is the ongoing process of conceptualization and emotion. Or, as neuroscientists J. A. Scott Kelso and David Engstrom put it, ‘The body is crucial to our experience of the world because it provides the sense organs through which the objective world is accessed by us and it has the organizing capacity of the mind that processes and constructs an understanding of that data. Organisms are not just pieces of matter; they are matter in motion – animate forms. […] Coordination dynamics (the study of how human beings and human brains – singly and together – coordinate behavior) has stressed the coevolution of real organisms coupled to and acting in real environments, a view captured in the term “embodied cognition.”’7

Our Bodies are Crucial


The body is thus crucial to our experience of the ‘world,’ since it provides us with the sense organs through which the ‘objective world’ is accessed by us. The input through our sense organs is then further processed by our sophisticated complex mental activities; these become our ‘experience’ or knowledge of the world. Experience which originates for us through our sense organs, then, is not simply sensation or perception but is also embodied, unified, and interpreted with the mind’s organizing, processing, and constructing our ‘sense’ of the world.

This analysis is emphasized in the Buddha’s teachings, with the crucial importance of how the body operates; it also places a different perspective on what is now found in many Buddhist meditation practices as well as in teachings regarding the body. Often, the body is taught in a negative light as an encumberment, a heap of unwanted bile, pus, and cells, a burden. In fact, the emphasis of numerous Buddhist interpretations is mainly on impermanence and encourages bhikkus (monks) to feel disgust with their bodies in order to create an attitude of nonattachment. For example, the common ‘corpse meditation’ is considered to be a particularly powerful method to develop disgust toward our bodies; this is then supposed to cut our attachment to sensual pleasures, such as sexuality or pride in appearance.

An example of this attitude, as Hamilton writes in Identity and Experience,8 can be found in an often cited text by the 5th century AD Indian Buddhist scholar Buddhaghosa. It has been translated as: ‘Wherefore, monks, be ye disgusted with this body.’ However, in Hamilton’s opinion, a more appropriate translation (both in this specific text and the wider context of the Buddha’s teachings) is: ‘So monks, be indifferent towards or dis-enchanted with your body.’ Hamilton posits that this second interpretation of the passage, and the accompanying general attitude – rather than encouraging bhikkus to feel disgust and repulsion towards their ‘impure’ bodies – is meant simply to discourage them from identifying with their bodies. The early Buddhist attitude toward the body was neither positive nor negative but neutrally analytical. In fact, the Buddha repeatedly encouraged a healthy lifestyle and care for the body.

A quote attributed to him is: ‘To keep the body in good health is a duty…otherwise we shall not be able to keep our mind strong and clear.’ This perspective is stated by Dr. Pinit Ratanakul:

‘In the Buddhist perspective the unique body of each of us, both in appearance and structure, is a result of our past kamma. The human body is at the same time the means by which we contact the world and the physical manifestation of our mind. Being such an important instrument, the body must be duly attended to, i.e. one must not abuse it through unwholesome food, alcohol, drugs, or by taxing it with over-indulgence and deprivation. Even enlightenment, the highest goal of Buddhism, cannot be attained by the mortification of the body, as witnessed in the personal experience of the Buddha. This is due to the interdependency of the mind and the body (mind and the body are also labeled name and form). Intellectual illumination can be attained only when the body is not deprived of anything necessary for the healthy and efficient functioning of all bodily organs.’9

So, as we see in all of his teachings, the Buddha did not teach revulsion but an analytic and pragmatic Middle Way in our attitude toward our bodies.



The other khandhas engage in our intricate cognitive activities, and the necessary condition for all of the activities of the khandhas is consciousness. Consciousness is the activity of being conscious or aware and is dependent on the operation of the organic integrated whole of the khandhas, not individual aggregates acting in isolation from each other. Even though our attention becomes selective, narrowed, and focused on one awareness in a given moment, the general process of knowing what one is aware or knowledgeable of is called the khandha of consciousness.

Evan Thompson wrote about the brain basis of consciousness model called the Unified Field Model, as developed by Professor John R. Searle, which echoes the Buddha’s conception of consciousness: ‘According to this model (the Unified Conscious Field) the neural substrates of individual conscious states should not be considered sufficient for the occurrence of those states, for those states themselves presuppose the background consciousness of the subject. Any given conscious state is a modulation of a preexisting conscious field. An individual experience or conscious state (such as visual recognition of a face) is not a constituent of some aggregate conscious state, but rather a modification within the field of a basal or background consciousness: “Conscious experiences come in unified fields. In order to have a visual experience, a subject has been conscious already, and the experience is a modification of the field.”’10

In other words, Searle, like the Buddha, is advocating that the process of consciousness be understood not as manifested through separate individual ‘piles’ of experience but as an integrated ‘unified’ whole.


The final three khandhas – sensation, apperception, and volition – explain how incoming sensory data filtered through the ‘mind’ and awareness become our knowledge, or what we know. Again, we need to remember that we do not attend to our raw sensations one at a time; this process is, therefore, not linear. Rather, many inputs course through the various sense organs as well as bodily sensations that the ‘mind’ sorts out, and then specific inputs are given conscious attention within the unified field. McGann states: ‘Cognition is not added to perception after the fact, because it is inherent in the process of perception itself, it is part of what continually initiates, drives and structures the act of perceiving. An enactive approach to perception thus maintains a strong distinction between sensation and perception. Perception, wrapped up as it is in cognition, action, sense-making, is an activity embedded within, contextualized by, value driven intentional action. Sensation is an aspect of an embodied agent’s interaction with the world, an important part certainly, but not one with any veto or absolute authority as the character of experience.’11

This is clearly different from the traditional intuitive stage-like description of perception which holds modalities as basic ‘modes of presentation’ in which a perception is simply ‘presented’ to us as is – as visual, gustatory, tactile, or the like. All other aspects of perception (recognition of the object, interpretation of the event) involve some form of further, often inferential, cognitive operation; perception mingles with cognition. In other words, it’s not just what the sensory organs are doing, but what the brain is already doing, that is involved in perception.

Sensations are vipaka, which are whatever you initially experience through the senses of sight, hearing, smell, taste, or touch. We first have an impinging of incoming sensory data but are unaware of the ‘pure’ sensation and experience of it because it is still too early for the data to reach a necessary threshold to register it. In this pre-reflective stage, experience is direct, immediate, and intuitive. Subject and object, inner and outer, are unified. This is the khandha of sensation. Every perceptual experience is an experience of my body.



Next come discrimination and identification, which are associated with the khandha of apperception. In modern terms, this equates to cognitive functioning – an intellectual constructive process by which one becomes aware of, perceives, or comprehends ideas – and it involves all aspects of perception, thinking, reasoning, and remembering. One identifies more clearly or becomes perceptually aware when what was previously only a sensation (the impinging data) reaches a certain threshold, triggering impulses in the receptor neurons that register in the brain through various mediating processes. It is through this process that we identify things individually by contrasting and distinguishing them from their surrounding contexts, independently from us, and giving them a separate continuity. ‘Ideas’ about the object mingle with the awareness of its sense presence: we name it, categorize it, and compare it to other things. Seeing a color is vipaka, but conceptualizing our like or dislike of it is not. Names, features, and what seem to be independent objects are the products of this reification process and are dependent phenomena. Importantly, the independent status of objects is purely an attributed state. They are only distinguished contrastively, and they no longer correspond to an original ‘pure’ sensation, because they are now the result of a complex, constructive neurological process.

Take, for example, the act of seeing, or looking at a flower, to distinguish what characterizes the stage of sensation, or immediate awareness, from that of apperception, or ascertaining distinguishing features of an object. In the first instant of experience, the flower and the observer are one. The impinging stimuli hasn’t yet reached the threshold that triggers registration in the cortex. The flower is seen and the seeing of it is one indivisible act, which is the datum, or the ‘pure sensations’experience. But to cognize and then declare that the flower is a flower and, more specifically, a yellow rose, involves interpretation, which is an abstracting process. What is now experienced is not an immediate, unmediated sensation, but the outcome of a complex, constructive cognitive process. Therefore, a sensation is defined as the contact between sense organ and sensory input, as well as the consciousness that results from their contact. After the direct experience, the sensations are processed by a complex, constructive neurological process and categorized and their significance established. As Hamilton writes, ‘One sees, hears, tastes, something. As such, though one refers separately to sense organs, sense objects and what is sensed – nose, cheese, smell, for example – this separation is, in fact, an abstraction from the experience “smelling cheese-smell.”’12 It is in this reflective phase of perception and conceptualization that experience becomes a constructive process and that sensations are interpreted in light of past experience, including cultural and linguistic constructs and individual interests and preferences.

Writer and philosopher Alva Noë makes a similar point about the difference between sensations and perceptions when he argues:

‘In general, there are reasons to doubt that tactile sensation or feeling is sufficient for tactile perception. To perceive by touch, for example, the rectangularity of something you hold in your hands, or the layout of furniture in a room (as a blind person might, by moving around and reaching and touching) is not merely to have certain feelings or sensations. After all, the rectangularity is not captured by specific sensations. There is no unitary sensation or feel of a rectangle. The rectangularity is made available to you, in touch, by your active touching (probing, prodding, stroking, rubbing, squeezing) with your hands. What informs you of the shape of what you feel or hold is not the intrinsic character of your sensations, but rather your implicit understanding of the organization or structure of your sensations.’13

Bhikkhu K. Ñänananda also makes a relevant observation with this analysis:

‘Suppose there is a little child, a toddler, who is still unable to speak or understand language. Someone gives him a rubber ball and the child has seen it for the first time. If the child is told that it is a rubber ball, he might not understand it. How does he get to know that object? He smells it, feels it, and tries to eat it, and finally rolls it on the floor. At last he understands that it is a plaything. Now the child has recognised the rubber ball not (only) by the name that the world has given it, but by those factors included under “name” in nàma-råpa, namely feeling, perception, intention, contact and attention.’14

And finally, Sariputta, a chief disciple of the Buddha, declared:

‘Feeling, apperception, and cognitive awareness, friend – these factors are conjoined, not disjoined, and it is impossible to separate each of these states from others to describe the difference between them. For what one feels, that one apperceives; and what one apperceives, that one cognizes.’15

In the workings of the khandhas, the initial impinging of sense data are not enough for the grasping of what the initial data represent. Sensation and sensory knowledge must work together, for example, in the case of furniture, to produce the perception of the spatial layout of an object or a room. As Noë concludes, modeling any sense requires that we understand it not as something that concerns the brain alone but as something involving ‘the animate body and the world. I propose that to perceive is not merely to have sensation, or to receive sensory impressions, it is to have sensations that one understands […]. The enactive view insists that mere feeling is not sufficient for perceptual experience (i.e., for experience with world-representing content).’16

As the Buddha explained, the process of selection begins at the initial non-reflective stage when attention creates the necessary threshold and then moves to the self-conscious stage of apperception. David J. Kalupahana explains:

‘Selectivity based upon “interest” occurs even in the pre-reflective stage beginning with the impinging of the sense object with the sense organ culminating in feeling or sensation. The need for selectivity even at this initial stage of sense experience is prompted by the inability of consciousness to deal with the “big blooming buzzing confusion.” During the second stage, when sensations give rise to perception and reflection, the selectivity is conditioned by the stronger “dispositions” or habitual tendencies, thereby leading to obsession and bondage during the final stage. This selectivity in consciousness accounts for the possibility and, therefore, the ability on the part of the human being to choose, think and act, and these represent the core of selfhood or personality in the Buddha’s doctrine.’17

For William James, the making manifest of what is attended to by the sensations is the result of what he called attention, which is selection: ‘Out of what is in itself an indistinguishable, swarming continuum, devoid of distinction or emphasis […] Attention […] picks out certain sensations as worthy of notice, choosing those that are signs to us of things which happen practically or aesthetically to interest us, to which we, therefore, give substantive names and to which we give the status of independence and dignity.’18

So while selection or attention is based on an inherent or learned focus as well as on our organic biological makeup, it isn’t until the selected sensation is cognitively recognized, named, and interpreted that it moves into the realm of apperception. There are two aspects of a single, represented, integral event – two poles (subject/object) with consciousness linking them together.



The fifth khandha, volition, is the most complex aspect of our cognitive apparatus. We have affective responses to whatever we experience; these can be pleasant, unpleasant, or neutral. A neutral response is to merely register a sensation and become aware of it simply in a non-attached, factual sense. When we consider an experience to be pleasant, on the other hand, we become attached and want it to continue or be repeated. These desires or cravings become preferences and choices and therefore originate in our cognitive apparatus; they can range from minor preferences in the positive domain and mild aversion in the realm of the negative to very profound affective states in both. These affective states are responses not only to bodily sensations, but also to abstract concepts and beliefs; they are established on, among other things, one’s beliefs, desire to continue to exist (or not), self-identifications, traditions, customs. They can also be such general desires as to be loved, successful, accepted, happy, wealthy, not alone, not poor, or not unhappy. These biases and inclinations make up our psychological orientation and represent our ‘world.’

According to the Buddha, our affective volitional characteristics fuel the kammic process and continue until our last affective volitional states are extinguished with Enlightenment. Their continued functioning is conditioned (dependently originated) by the level of ignorance or insight on which we are operating. As we better understand how to see things ‘as they are,’ the degree of our ignorance – and, therefore, our volitions – becomes differently conditioned. To return to the work of David J. Kalupahana: ‘The Buddha insisted that desire is not identical with the variegated objects in the world. It is the thought of lust which is generated by wrong ideas or misconception, primarily the metaphysical conceptions of self and object. As such it is possible to maintain that on occasions of sense experience, which are represented by the coming together of the subject and object, the subject does come to be affected in a certain way and this is conditioned by views it holds regarding its own nature as well as the object.’19

We cannot separate ourselves from our experience, which is organically based and which takes place through the khandhas. It is the understanding of the operation of the khandhas that is the focus of insight meditation. We clearly see that dukkha is intimately linked with our cognitive experience and is not just a description of the world in which we have our experience, or of what we perceive and then react to. Since our affective-volitional apparatus, which fuels our continuity, is cognitively based, dukkha is also. The cessation of suffering, or Enlightenment, is a radical cognitive re-orientation. The Buddha taught that our cognitive experiences and phenomena are dependently originated, dynamic, ever-changing, and impermanent. This is the Truth of experience.

The Buddha’s teachings focus on epistemology, or how we can know about reality, and they assign primary importance to the workings of one’s constructive and categorical cognitive apparatus. They are not ontological or based on the study of fundamental categories of reality. Unfortunately, this significant but subtly expanded understanding of the Buddha’s teachings is often missed in contemporary Buddhist teachings. For example, in a discussion about the Buddha’s perspective on suffering, Adam Miller writes, ‘Sensation is suffering. Sensation takes place only when a sensor is affected, stimulated, irritated, perturbed, or pressed upon. We see only when light perturbs the eye, we hear only when sound perturbs the ear, we think only when thoughts perturb the mind. It is in light of the constant, relentless pressure of sensation in all its modalities that life is suffering.’20

We have seen, though, that the Buddha taught dukkha, not as the simple occurrence of sensations of inputs alone, but as the secondary processing which then identifies, contrasts, classifies, and creates pleasure or discomfort and then desires or craves or rejects as a consequence of cognition. In the Second Noble Truth, the Buddha clearly teaches that dukkha is our pre-enlightened constructed experience.

Cognition after Enlightenment


Often, also, there is confusion as to how the Buddha, as a human being, experienced life cognitively after his enlightenment. To end suffering, an Enlightened One does not become a ‘robot’ that transcends worldly sense experience or someone who denies the reality of the world of sense experience. Quite the contrary: the operation of the five khandhas becomes intimately known and accepted. The grounding of Enlightenment as a cognitive event leaves intact the locus of experience in the body, and the post – Enlightenment life experience becomes quite reasonable and understandable.

In fact, if we accept biologist H. R. Maturana’s concept of autopoiesis21 – that living systems are ‘self-producing’ organisms which maintain their particular form despite material inflow and outflow, through biological self-regulation and self-reference – we can consider the Buddha’s biological existence to have continued as before his Enlightenment. The biological, physical functions of sleep/wakefulness, hunger/satiation, fatigue/alertness, and so on, as well as smelling, tasting, seeing, hearing, touching, and thinking would have remained the same. These physical conditions only ended upon the Buddha’s death. The Buddha made the distinction between the experience of living which is grounded in the body and in the khandhas and the ignorance of a cognitive schema in which a subject/object dualism exists. Actually, the Enlightenment experience allowed the Buddha to move in the world unhindered by the ordinary restrictions borne of our ignorance in referring naively to our dualistic cognitive constructions.

Another source of confusion has to do with the ‘I’ of an Enlightened One. As Kalupahana explains:

‘In the context of the five aggregates (khandhas), the Buddha was not reluctant to speak of “I” or “myself” or even of the “self.” Without admitting to a “ghost in the machine” or a transcendental apperception, the Buddha was willing to recognize the feeling of individuality, of self. It is a feeling that can contract and expand depending on the context. It does not represent a static entity to which everything belongs. […] There seems to be no justification for assuming the Buddha encouraged the annihilation of this feeling of self. Indeed, the reality of feelings and emotions that occur in the stream of experience are relevant to an explanation of harmonious life. […] Thus the Buddha spoke of “I” or “myself” and “mine” but avoided and discouraged “I-making” or “mine-making,” both terms imply egoism. The feeling of self-occurring thus turns out to an important element in the affirmation of the relation of dependence that exists between a person, his family, nation, humanity, as well as nature.

The solidification of this feeling into a ‘pure ego’ can interrupt its extension at any level, confining it exclusively to the neglect of every other. As such, it can lead to extreme selfishness, to tribalism, to nationalism, or to pure altruism. For the Buddha, the so-called self-feeling is dependently arisen, and, is therefore contextual, not absolute.’22

As much as the Buddha emphasized the elimination of egotism, he did not intend the annihilation or depersonalization of what modern psychology labels the empirical self or the individual experiences. The terms ‘I’ or ‘self’ are pragmatic conventions that reflect the living experience that all conscious living beings have.

Khandhas and Awakening


With Enlightenment, the Buddha came to a sudden realization or epiphany about the nature of ‘existence.’ The basis of his enlightened was having had the ‘pure experience’ of emptiness or Nibbāna (Sanskrit: Nirvana). It was only when he experienced this state of no-thingness that he understood the mechanism of the creation of cravings and desires which, in turn, causes the dukkha of our lives. Upon Enlightenment, he comprehended that it was his ‘mental apparatus’ that had in ignorance created his desires and cravings; therefore, it is the process and organization of our systematic mental organization that needs to be understood and altered in a radical way, and to do this we must understand the khandhas.

What the Awakening insight reorients is our understanding of how the cognitive apparatus creates craving and dukkha. The Buddha was concerned with the spiritual and existential suffering of sentient beings, and his Awakening showed him that our world is completely subjectively constructed, and that what the cognitive apparatus creates or imagines is dualism (most notably, subject-object dualism). Therefore, the Buddha’s teachings focus on understanding the workings of our bodies as embedded living organisms and the process of how we ‘experience’ living and knowing.

Upon achieving a correct understanding of the nature of our constructions of reality and the consequences thereof, the Buddha attained Enlightenment; this extinguished the fuel of the fire – the desires and cravings – of continuity (the cycle of rebirth). He taught the way for us to also achieve Nirodha and become Awakened. Dukkha is based not solely on impermanence but more profoundly on how we construct our ‘world’ and cling to the illusions we construct – our pre-enlightened experience.



Lewis, C. I., Mind and the World Order: Outline of a Theory of Knowledge (New York: Dover, 1956), 29.

Wisdom Library, Buddhism in Ottawa: “Glossary of Buddhist Terms” ( Retrieved 3 June 2013.

Thanissaro, B., “Five Piles of Bricks: The Khandhas as Burden & Path” in Access to Insight, 5 June 2010.

Davids, C.A.F. Rhys, “Intellect and the Kbandba Doctrine” in Buddhist Review 2:1, 1910.01-03, 104.

Enactive approaches in cognitive science propose that perception, and more generally cognitive experience, are strongly mediated by embodied (sensory motor) processes, and that our primary experience of the world is action-oriented or pragmatic (Noë 2004; Thompson 2007; Varela et al. 1991). Adams, F. and Aizawa, K., “The bounds of cognition” in Philosophical Psychology 14 (1): 43-64.

Varela, F. J., Thompson, E. T. and Rosch, E. (1991) The Embodied Mind: Cognitive Science and Human Experience (Cambridge, Massachusetts: MIT Press, 1991), 59-80.

Hamilton, S., Early Buddhism: A New Approach: The I of the Beholder (Routledge Critical Studies in Buddhism) (New York: Routledge, 2000), 73.

  1. A. Scott Kelso and Engstrom, D. The Complementary Nature (Cambridge, Massachusetts: MIT Press, 2006), 87, 89.

Hamilton, S. Identity and Experience: The Constitution of the Human Being According to Early Buddhism (Oxford: Luzac Oriental, 2001), 181.

Ratanakul, P., “Buddhism, Health and Disease”, Eubios Journal of Asian and International Bioethics 15, 162-164.

Thompson, E., Mind in Life: Biology, Phenomenology, and the Sciences of Mind (Cambridge: Harvard University Press, 2007), 351.

McGann, M., “Perceptual Modalities: Modes of Presentation of Modes of Interaction?” (http://lifeandmind.files. – modes-of-perception-or-modes-of-action1.pdf). Retrieved 3 June 2013.

Hamilton, S., Early Buddhism: A New Approach: The I of the Beholder (Routledge Critical Studies in Buddhism) (New York: Routledge, 2000), 163.

Noe, A., Action in perception (Cambridge, Massachusetts: MIT Press, 2004), 15.

Access to Insight, ed., “Majjhima Nikaya: The Middle-length Discourses”, in Access to Insight, 23 April 2012 ( Retrieved 15 June 2013.

Noe, A., Action in perception (Cambridge, Massachusetts: MIT Press, 2004), 16.

Kalupahana, D. J., The Principles of Buddhist Psychology (Albany, New York: State University of New York Press, 1987), 89.

Shaw, M., “William James and Yogaacaara philosophy: A comparative inquiry.” Philosophy East and West 37(3), 228.

Kalupahana, D. J., The Principles of Buddhist Psychology (Albany, New York: State University of New York Press, 1987), 97.

Miller, A., “The Root, The All” ( Retrieved 3 June 2013.

Maturana, H. R. and Varela, F. J., Autopoiesis and Cognition: The Realization of the Living (Dordrecht: Reidel, 1980).

Kalupahana, D. J., The Principles of Buddhist Psychology (Albany, New York: State University of New York Press, 1987), 38.


The importance of our body

26 Jan



Life Actualization

18 Jan



Meaning of Life

6 Jan



Life Cherishes Itself

30 Dec


Li and Chi representing hidden and manifest Actuality

5 Apr

Li and Chi representing hidden and manifest Actuality

After reading Ruth E. Kastner’s book, Understanding our Unseen Reality, (2015) and re-reading sections of R.G.H. Siu’s book, Chi, (1974), out of an interest, I decided to speculate about an apparent commonality between two perspectives. While throughout the history of Chinese philosophical thought the expressions Li and Chi have had significantly diverse meanings, this short paper compares Li and Chi to the new noumenon and phenomenon aspects described in the Transactional Interpretation of quantum physics.

Chuang Tsu, Chinese philosopher of the 4th Century BC, had described characteristics of Chi as “When the Chi condenses, its visibility becomes apparent so that there are then the shapes (of individual things). When it disperses, its visibility is no longer apparent and there are no shapes. At the time of its condensation, can one say otherwise than that this is but temporary? But at the time of its dispersing, can one hastily say that it is then nonexistent?” For Tsu, Chi/Qi described vital force functions as the dynamic force out of which all objects or events emerge and into which they all return when their manifestation is completed.

Chu Hsi, an important neo-Confucian Chinese philosopher, (1130-1200) expanded on this concept by stating that there is ‘Li’ which is the underlying yet hidden base essence of the universe, and Chi is the expressed Li in concrete form. He wrote: “In the universe, there are Li and Chi. Li is that which pertains to what is before shapes, and is the source from which all things are produced. The Chi is the material (literally, instrument) that pertains to ‘what is within shapes,’ and is the means whereby things are produced. Hence men or things, at the moment of their production, must receive this Li in order that they may have a nature of their own. They must receive Chi in order that they may have their bodily form.” (Reply to Huang Tao-fu, Collected Literary Writings)

Therefore, Chi is described as the condensed material that creates and is expressed in the uniqueness of the many myriad forms of the macroscopic, spacetime world giving rise to everything manifested. On the other hand, Li, of the microscopic or, I suggest, quantum world, is the essence for the macroscopic world. That is, it is in the realm of ‘no things’ or virtual, that is Li. Hence, a ‘thing’ is a concrete manifestation of Li and it therefore, possesses Li from the first moment of its existence. It is Li that makes things what they are. Thus, according to neo-Confucianism, all categories of objects, sentient or not, possess Li. Since manifested Chi depends upon the Li for its operation, when there is an agglomeration of Chi, Li is also present within it. Chi is the Li as the capacity to condense and thus form things. Yet, the Li constitutes only a pure and ‘empty’ world, without shapes or traces. “But the Chi is the capacity to undergo fermentation and condensation, and thus bring things into existence. And yet, whenever the Chi exists, the Li is present within it.” (Recorded Sayings, chtian 1.) The Chi that moves is called the Yang; the Chi that rests is called the Yin. Thus, according to Chu Hsi, the dualistic elements that are the fundamentals of the universe in Chinese cosmology are produced. He says: “Whereas the Yang is in movement and the Yin in quiescence, the Supreme Ultimate is neither in movement nor in quiescence. But there are the Li of movement and of quiescence. These Li are invisible, and become manifest to us only when there are the movement of the Yang and the quiescence of the Yin. The Li rests upon the Yin and Yang just as a man rides on a horse.” (Complete Works, chiian 49.)

We recognize a similarity of Hsi’s Li and Chi to Kastner’s description of the transaction process that creates spacetime and the manifest objects that are found there. This consists in the idea that there is more to reality than spacetime, and that quantum theory is what describes that subtler, unseen reality. In this hypothesis, quantum processes take place in a realm scaffolding the spacetime realm. Quanta are not contained in our spacetime world but in the realm of possibilities outside spacetime. Kastner explains that according to the transaction interpretation of quantum systems, such as electrons, travel by what is a physical entity called an offer wave , which is offered from a source called an emitter, to a destination called an absorber. The microscopic emitters and absorbers are quantum objects and not in spacetime. When there is absorption of the offer, this process gives rise to a confirmation wave that travels back to the emitter. This process of an offer responded to by a confirmation is the basic ‘handshake’. The confirmation is also like a mirror image of the offer representing an incipient transaction whose essence is merely possible energy rather than real energy. The process of the creation of new particles can only be treated by relativitsic quantum mechanics.

Once there is a matching confirmation, then the property is defined as actualized, brought into spacetime and is a classical property. The incipient transaction is actualized and becomes an observable event in the macroworld.A spacetime object begins at the point at which a confirmation has been generated. Real energy is only conveyed in the actualized transaction, in fact, only through an actualized transaction can real energy be radiated or transferred from one object to another. So indeed, a reliable macroscopic object is a consistent absorber and can be defined as a system of many actualized transactions. Kastner uses the example of a geiger counter to illustrate the difference of the two ‘worlds’. A geiger counter exists as an object in the macroscopic world being a conglomerate of actualized transactions. But it also maintains its roots in the quantumland domain of possibilities because it is comprised of atoms, which can act as emitters or absorbers. Measurement occurs both whenever an absorber is accessible to an emitter and when confirmations are generated.

So we can consider that the emitted offer wave from ‘quantumland’ or ‘Li’ is actualized in the transaction or ‘Chi’ created from the process at the inherently unpredictable quantum level to the macroscopic level of transformed spacetime events. In fact, there is no spacetime or things and substance apart from those transforming events. In the subtler level of uncertainty or quantum, emission or absorption of transaction are not automatically assured, they are only tendencies: the swapping of virtual quanta which do not participate in energy transferring transactions unless they are elevated to offer waves or real photons.

The distinction between macroscopic world and microscopic or quantum world is made when classical physics describes the macro of atoms and other fundamental components of matter while the underlying hidden actuality corresponds to the quantum level. For humans then, the essence of existence is fundamentally ‘quantumland’ or Li while our experienced Actual as expressed through Chi is the manifested in spacetime.

So everything around us is the result of an actualized event established through actualized transactions. This is the world of appearance or spacetime. But all those events are brought into spacetime from the vast unseen hidden reality of quantumland which exists as the essential scaffolding that supports our spacetime world of experience. In this light, it becomes possible to clearly draw the similarities between the Chu Hsi’s Neo-Confucian concepts of Li and Chi with Kastner’s proposed operation of quantumland and spacetime. This matching of perspective helps to illuminate the position of both on the operation of forces in the universe.

BioTensegrity – body mechanics

14 Dec
  • This is really interesting as a model of biologic structures. Here is an article (edited for space reasons) by Stephen M Levin MD and others that hit on some key points.



The Mechanics of Martial Arts

Eastern philosophy has not had a physical model for martial arts that a western trained mind could wrap a thought around. That is, not until biotensegrity.

The symbol of strength for western culture is the Greek god, Atlas. After a mythical war between the Olympians and Titans, Atlas, one of the losers, was condemned to stand as a pillar and support the universe on his shoulders for all eternity.

Following this model, strength, in western thought, is characterized as a rigid, unyielding and unmovable column. Western thought has the rigid column, the lever, and brute force, all concepts familiar to us since childhood when we built our first stack of blocks, rode a seesaw and smashed our first toy. In eastern thought, strength comes from deep within and is flexible, yielding and mobile; it flows. This difference in philosophy of strength is expressed in a difference in approach to combat sports. But eastern philosophy has not had a physical model for martial arts that a western trained mind could wrap a thought around. That is, not until biotensegrity. Biotensegrity is a mechanical model of biologic structure and function based on construction concepts introduced by Kenneth Snelson and Buckminster Fuller in the 1960s. In these models, the compression struts or rods are enmeshed and float in a structured network of continuously connected tension tendons. The shafts constructed by tensegrity networks are as different from a conventional column as a wagon wheel differs from a wire spoked bicycle wheel. Let me explain.

A conventional column is vertically oriented, compression load resisting and immobile. It depends on gravity to hold it together. It can only function on land, in a gravity field. The heavy load above fixes it in place. It must have ground beneath it for support. The weight above crushes down on the support below and the bottom blocks must be thicker and stronger than what is above it. If the spine is a conventional column, the arms and legs will cantilever off the body like flagpoles off a building. Moving an up-right, multiple hinged, flexible column, such as the spine as envisioned in conventional biomechanics, is more challenging than moving an upright Titan missile to its launch pad. Walking and running have been described as a controlled fall, a rather inelegant way to conceptualize movement. It certainly doesn’t describe the movement of a basketball player, a ballet dancer or a martial arts master. In the standard spine column model, the model for mobilizing the spine and putting the body in motion would be a wagon wheel.

In a wagon wheel, each spoke, compressed between the heavy rim and the axle, acts as a column. The wheel vaults from one spoke/column to the next, loading and unloading each spoke in turn. The weight of the wagon compresses the single spoke that then squeezes the rim between the spoke and the ground. At any one time, only one spoke is loaded and the other spokes just stand there and wait their turn. The spoke must be rigid and strong enough to withstand the heavy compression load and short, thick spokes do better than long, thin ones. The rim must be thick and strong, as it would crush under heavy load as it, too, is locally loaded. The forces are generated from the outside to the center. Using the column, post and lintel model, in a standing body, the heel bone would have to be the strongest bone in the body instead of, as it is in life, one of the weakest and softest. Biotensegrity bodies would be like a wire-spoke bicycle wheel. In a wire wheel, the hub hangs from the rim by a thin, flexible spoke. The rim would then belly out if it were not for the other spokes that pull in toward the hub. In this way, the load is carried by the tension of the many spokes, not the compression strength of one. The load gets distributed through the system and the hub is floating in a tension network like a fly caught in a spider web. All spokes are under tension all the time, doing their share to carry the load. They can be long and thin. Even loads at the rim become distributed through the system so the rim does not have to be thick and strong as in a wagon wheel. The structure is omnidirectional and functions independently of gravity. Unlike a conventional column, it is structurally stable and functional right side up, upside down or sideways. A tensegrity structure can function equally well on land, at sea, in air or space. Now think of each cell in the body behaving structurally as if it were a three-dimensional bicycle wheel. Each wheel would connect to each adjacent wheel the cell level, up the scale to tissue, organ and organism, a wheel within a wheel within a wheel.  In this system, all connective tissues in the body work together, all the time. It known, by recent experimental work that all the connective tissue, muscles, tendons ligaments right down to the cells are interconnected in just this way.

The body model would be more like Snelson’s Needle Tower where the bones of the tower are enmeshed in the wire tendons, never touching or compressing one another. Unlike flagpoles attached to the side of a building, the limbs are integrated into the system. The energy flows from deep within the structure, chi, out to the tips of the fingers and toes. The basic building block of the biotensegrity structures, the finite element, is the tensegrity icosahedron.

We need not go into all the details of the evolution of the biologic body here, but there are some very special properties of the icosahedron that explain the particular characteristics of the biologic structure. It is, mathematically, the most symmetrical structure and, in its resting state, is extremely energy efficient. Distorting the shape requires energy and when that energy is released, it returns to its least energy state, a, normally, self-regulating and self-generating mechanism. It is like a spring that, when distorted, will bounce back to its original shape. But it is a very special spring. When a steel spring is in its resting state, there is no energy storage. Adding a weight, say a kilo, will stretch the spring a defined amount, say 10cm. Each additional kilo will stretch the spring an additional 10cm. When the spring is released, all the stored energy is immediately released and the spring will snap back. If it is not restrained, it will bounce because of the accelerated motion. And, depending on how springy elastic it is, it will bounce and bounce and bounce, jerking up and down. This is the type of spring associated with the standard column, post and lintel construction of the body in western mechanics and is characterized as linear behavior.

The icosahedron, tensegrity spring is different and characterized as nonlinear. In the resting state, there is always some residual tension or tone in the system so it is never completely relaxed. If you add a kilo weight it may distort 15cms. But add another kilo and the distortion may only be 7cms, then 4cms, then 1cm. The icosahedron spring gets stiffer and stronger as you load it.

You can see that as you add more weight a great amount of energy can be stored with very little change of shape of the icosahedron spring. When released, there is not the sudden, total release of stored energy as there is in a linear spring, but a great amount of energy can be released early and the last part can be released slowly and gently; a splashdown rather than a hard landing. This softens the blow and removes the bounce and jerkiness. As noted, not all the energy is released, some remains in storage. Grab onto your earlobe and pull. At first, it distorts easily, but then it stiffens and pulling on it doesn’t change the shape very much. Let go. It regains most of its original shape quickly, but the last bit is very slow. It does not bounce back like a rubber band and slap you on the side of the head. This is often termed in biomechanical circles as visco-elastic as it has properties that in some ways are like fluid and in other ways, like a stiff elastic spring. In biologic bodies with bones, the stiffest icosahedrons are the bones and the most energy can be stored there. When compressed or expanded the movement of the icosahedron is helical, like the threads of a wood screw, and this is consistent with what we know of normal body movement. When it behaves as a stiffening fluid, it becomes a shock absorber, soaking up the energy rather than focusing it.

Those of you who are martial art practitioners already know you don’t stand stiff and upright but move in all directions like a break-dancer. You know that the energy flows in and out from deep within the system and that you can bring energy up from the squishiness of your cells out to harden on the tips of your fingers. Your body is never completely flaccid; some tone always remains in the system. To get the maximum energy you screw yourself down and then explode with tremendous force from within, but never overshoot your mark. Pulling the force from deep within your structure is recruiting the entire body mass. Newton’s second law of motion is force equals mass times acceleration F = ma. Imagine the difference if a small car moving at 5MPH strikes your automobile or a bus moving at 5MPH strikes your auto; quite a difference. Consistent with that law, striking a blow with your whole body creates a greater force than just striking with your fist, as you are increasing mass. In the standard post and lintel model, the arm and fist are just hanging off the body mass and operate independently of it. In a conventional boxers blow, speed a is all-important as the mass m is mostly the fist, in the biotensegrity model, the entire body mass is involved. When absorbing a blow, it reverses the process by soaking up the initial force, distributing it, and then gradually stiffing at the cellular level where the cells, rather than all the resistance landing on a local area. The bone breaking impact, rather than focused where the blow landed, will be he resisted by all your cells in a wave that spreads from the impact site to a wall of billions of cells throughout the body, acting as perfect hydraulic shock absorbers, take up the blow. You go with the flow. Much of what seems unexplainable about the forces generated in martial arts are readily explained when the body is understood as a biotensegrity structure rather than as the common western post and lintel model.

The concept that the body is a tensegrity structure is not just a convenient model for martial arts practitioners. A turf toe injury in a quarterback will keep him from throwing a long pass.  The quarterback throws from his foot, not just his arm. We know that biologic tissues characteristically behave as nonlinear and visco-elastic material. In fact, this nonlinear behavior has been felt to be an essential quality of living tissue. Different researchers in different parts of the world have demonstrated evidence that the entire fascial network is interconnected so that a continuous tension network is known to exist within the body. We also know that at least some of the joints, like the shoulder girdle, transmit their loads through the tension of the soft tissue and not the compression of the bones. There is mounting evidence that this is the way all joints work. It is difficult to let go of concepts that have been part of us since childhood. The post and lintel lever system have intuitively been our model of how the body mechanically functions. On the other hand, we really know better. Just watch any child first learning to throw a ball. Our first throws are done as if the arm is a separate structure, detached from the body. We soon learn that to throw a ball, you must put your whole body into it as the football quarterback does. We just never had a model to understand what we were doing. Biotensegrity gives us that model. 2010 Stephen M Levin

———————————————————–Dr. Stephen Levin’s research in Biotensegrity holds the view that the body is a tensegrity truss system with tension members provided by a matrix of connective tissues, ligaments, muscles, blood vessels, nerves and fascia.

In this model, the bones are considered as spacers, not weight bearers along with incompressible fluids giving shape and form to a soft tissue entity.

Water in its structured form is enclosed in the body in fascial compartments. It helps to provide shock absorption and holds the shape of a tissue. The different densities of liquids contribute to their form as either a sol or gel.

Therefore, as we move from liquid state to a denser tissue determines how the tissue reacts. This effect carries on through all tissues from fascia to bone.

Polymers are clusters of molecules that again have tensegrous properties. When polymers are in fluid solution, they can withstand great pressures.

As a polymer, the fluid in the synovial sacs prevents the approximation of bones during weight bearing and their shock absorbency. This concept was researched by Dr. Levin in the mid-1970s.

During an orthoscopy of a knee under local anesthesia, he kept the patient standing in a weight-bearing posture through the support of a tilt table. His findings demonstrated that as long as the ligaments were held intact then the joint surfaces of the knee crura could not be approximated.

Under Newtonian principles of weight-bearing structures, this would never be possible. These same principles apply to all structures and tissues in the body. In the visceral system, the organs must position themselves in a closed fluid system. Some organs are held in place by the aid of negative air pressure suction and others by fascial and ligamentous attachment.

They are subjected to the forces of compression and tension as we move around and as the organs function as air or fluid movers or digesting foods. The weight bearing and movement behaviour of organs are known as turgor. In this model, the organs can expand and have mobility and motility qualities and interact with all their peripheral attachments.

The serous fluids that lubricate the space between organs allow an omnidirectional fluid shape sharing ability. When this fluid has the quality of a gel it acts as a buffer or spacer and a shocked observer. Stresses are absorbed through the tension members of the fascia supporting and surrounding the organs.

The fascia is a connective tissue forming a continuously interconnected system throughout the living body. It’s formed of liquid crystalline material and has the property of acting as a semiconductor. When fascia is moved, it produces tension under pressure, which generates a piezo electric field. Piezo-electricity comes from the Greek meaning pressure electricity. Oschman, J

 Stress to tissues can result in a crystallizing of the tissue turning a gel state to a sol. This affects the viscosity of the fluid to a restriction of the normal mobility of two adjacent structures. This can restrict the movement of an organ resulting in its immune response and function being impaired.

This impoverishment can result in many symptoms on its downward spiral towards pathology.

Standard methods of evaluating the body were based on Newtonian physics but this model does not fit our upright bipedal movement against gravity.

Newtonian physics can measure and calculate the strength of structures and the stresses they become subject to.

Unfortunately, the body is still reviewed and described in outmoded mechanical anatomical terms. Until the concept of Biotensegrity, the laws describing anatomical movement were according to Newtonian principles.

The cells that make up the soft tissues in the body arrange themselves into geometric shapes that just keep repeating themselves.

When cells gravitate together, they are subjected to natural laws governing their grouping and shape. The law of closest packing is the most economical way of stacking organisms.

If you stack a number of balls in a box there will be space between the balls. In the law of closest packing, the balls could be arranged to fit as tightly as possible into the case. In the closest arrangement, you end up with forms of icosahedron shapes.

Because there are actually no joined structures the icosahedron is quite unstable. This

results in the icosahedron oscillating and generating an energy field. Levin. S

In the study of Biotensegrity, the smallest components of bone or tissue arrange themselves as icosahedrons. Icosahedrons form structures that can withstand compression or tension in any direction. They can stack to make large structures like a beehive construction.

 In a tensegrity structure, compression elements float in the interspace of the tension wires. In the body, this would relate to the vertebrae in the spine. Each subsystem (vertebrae, disc and soft tissue) would be a subsystem of the spines metasystem, like the beehive analogy.

When viewed in this way you can understand their role in balancing tension and compression when stress is applied to the human frame. Extracts from Spine state of the Art Reviews Vol , No 2, May 1995, Hanley and Belfast, Philadelphia, Ed Thomas Deman M.D

Loads applied to the body distribute their pressure through the network of tension elements to create a balance. Even a pressure load to a small bone will distribute the load through the whole system.

A natural movement strategy in tensegrity truss architectural form is the closest explanation of nature’s laws at work in the human frame.

Bones floating in compression, tension network can form into trusses and extend out from the body like a bridge. This makes the body a weight mover, not a weight bearer. So in walking and especially when you are on one leg, the balanced tension maintains the integrity. Hatsumi says that you must learn to float in your walk. Hatsumi (2003).

The ligaments and soft tissues are constructed with soft viscoelastic materials that behave non linearly Journal of Mechanics in Medicine and Biology Vol 2,3 and 4, 375-388 World Scientific Publishing Co.

The difference between a mechanical structure and a human in motion is this non- linear flexibility of choice in movement.

In Newtonian physics, a four-dimensional universe is often described as a giant clockwork in three-dimensional space manifesting linear processes in time Power Vs Force D, Hawkins.

In other words, movement of a structure is determined by a concept of causality.

One-step sequentially leading to the next in mechanical formation.

The human frame is not ruled by this concept and is capable of nondeterministic, omnidirectional change inside of movements. This is like changing the formation of a step when you realize you are going to trip.

Pressure does not act locally on the tissue or follow a specific anatomical route along muscles or fascia. It follows to the depth of the tissue change and can act in a non-linear dynamic way that matches the tension/compression changes to the damaged tissue. This is brought about by the ability to palpate deeply into tissue without force feedback being a resistant force.


In the art of Shinden, he told us that our energy or intent must come from the heart to our thumb to instigate the change. My initial understanding of this concept was to be sincere and benevolent or your intent to initiate healing in the client.

Although this is important, more recent research has demonstrated that the heart is the main generator of electricity in the body in the form of energy. Science also tells us that energy can neither be created nor destroyed, only converted.

In the visceral approach, you are focusing on the tension of fascia around the organs. We need to integrate the concept of one point approach to a tensegrous structure changing sol to gel in the tissue matrix.

Dennis Bartram November 2004

Updated April 2005 ——————————————————————————

The mechanical anatomy of a cell  In trying to reestablish a physical view of biology, Ingber has shown that cells, far from being formless blobs, use tension to stabilize their structure. And he has demonstrated, through two decades of experiments, that tensegrity not only gives cells their shape, but helps regulate their biochemistry.

Every cell, Ingber notes, has an internal scaffolding, or cytoskeleton, a lattice formed from molecular “struts and wires” not unlike the rigid tubes and tensed cables of Snelson’s sculptures. The “wires” are a crisscrossing network of fine cables, known as microfilaments, that stretch from the cell membrane to the nucleus, exerting an inward pull. Opposing the pull are microtubules, the thicker compression-bearing “struts” of the cytoskeleton, and specialized receptor molecules on the cell’s outer membrane that anchor the cell to the extracellular matrix, the fibrous substance that holds groups of cells together. This balance of forces is the hallmark of tensegrity.

Tissues are built from groups of cells, which Ingber likens to eggs sitting on the “egg carton” of the extracellular matrix. The receptor molecules anchoring cells to the matrix, known as integrins, connect the cells to the wider world. Ingber’s group in Children’s Vascular Biology Program has shown that a mechanical force on tissue is felt first by integrins at these anchoring points, and then is carried by the cytoskeleton to regions deep inside each cell. Inside the cell, the force might vibrate or change the shape of a protein molecule, triggering a biochemical reaction, or tug on a chromosome in the nucleus, activating a gene.

Ingber says that cells also have “tone,” just like muscles, because of the constant pull of the cytoskeletal filaments. Much like a stretched violin string produces different sounds when force is applied at different points along its length, the cell processes chemical signals differently depending on how much it is distorted.

“A growth factor will have different effects depending on how much the cell is stretched,” says Ingber. Cells that are stretched and flattened, like those in the surfaces of wounds, tend to grow and multiply, whereas rounded cells, cramped by overly crowded conditions, switch on a “suicide” program and die. In contrast, cells that are neither stretched nor retracted carry on with their intended functions.

Location, location, location Another tenet of cellular tensegrity is that physical location matters. When regulatory molecules float around loose inside the cell, their activities are little affected by mechanical forces that act on the cell as a whole. But when they’re attached to the cytoskeleton, they become part of the larger network, and are in a position to influence cellular “decision-making.” Many regulatory and signaling molecules are anchored on the cytoskeleton at the cell’s surface membrane, in spots known as adhesion sites, where integrins cluster. These prime locations are key signal-processing centers, like nodes on a computer network, where neighboring molecules can receive mechanical information from the outside world and exchange signals. “Adhesion sites are what’s important for major control of the cell,” Ingber says. “If you’re in one of these sites, you’re hooked up to a bunch of players, both mechanical and chemical. You can affect these players, which in turn affect a bunch of other players.”

Ingber offers the example of the oncogene src, one of the first genes known to cause tumors. This mutated gene doesn’t shut off – it sends unrelenting chemical signals telling the cell to grow. “But what’s interesting is that src is normally found on the cytoskeleton in the adhesion sites, near its signaling partners,” he says. “To produce a cancerous transformation, it must be at these sites because it needs to be integrated within the structure of the cell.”

Disease mechanics Based on these observations, Ingber believes that genes and molecules only partially explain disease origins. In fact, he asserts that many medical conditions are caused by a mechanical failure at the cell and tissue level. Examples include congestive heart failure, where the heart muscle loses its elasticity and becomes “floppy,” thus losing its pumping efficiency; and asthma, where changes in tissue mechanics cause the airway to stiffen, tighten and contract, increasing mechanical resistance and constricting breathing.

But often the mechanical basis of a disease is not so obvious. On an airplane not long ago, Ingber found himself sitting next to Jing Zhou, a researcher from Brigham and Women’s Hospital, who told him about her work on polycystic kidney disease, or PKD. In children with PKD, huge cysts form in the kidney tubules, eventually replacing much of the mass of the organ itself, and causing the kidneys to fail. Zhou’s lab had found a gene linked to PKD and localized it to a thin antenna-like structure sticking out of the kidney cell, known as the primary cilium. But she had no explanation for the finding.

Ingber pointed out that the cilium is designed to sense mechanical forces ¨ in the case of the kidney, the shear stress caused by urine flow. Normally, the force of the flow bends the cilium, triggering calcium to rush into the cell. He suggested to Zhou that perhaps cells affected by PKD have a faulty calcium signal and constantly “think” that shear stresses are high. This in turn might cause the tubules to enlarge more and more to accommodate the flow, eventually forming cysts. From this serendipitous meeting, a collaboration was born, and together, Ingber and Zhou showed that when the PKD-causing genes are disabled in mice, the “lever” of the primary cilium malfunctions and fails to trigger a normal calcium response.

Scientific heresy? Ingber has worked hard to defend the notions of cellular tensegrity and mechanical forces regulating cellular biochemistry. He recalls being publicly attacked while presenting at scientific meetings. But he also remembers an eminent scientist telling him, “If you’ve got them that upset, you must be on to something important.” And so Ingber returned to the lab bench. “I responded to my critics by devising experiments,” he says.

In 1993, his team reported in Science that when they used magnetic forces to literally twist the integrin receptors at the cell surface, the cytoskeleton stiffened in response to the stress and behaved like a tensegrity structure. In 1997, the team reported in the Proceedings of the National Academy of Sciences that tugging on the same integrin receptors causes changes in the cell nucleus. In 2000, a study in Nature Cell Biology demonstrated that mechanical stress at the cell surface causes the release of chemical signals inside the cell that kick genes into action. Tweaking receptors not linked to the cytoskeleton had no such effect. Other experiments have altered the extracellular matrix – making it alternately rigid or flexible – and documented effects on cell signaling and gene expression.

Nanotechnology and beyond Ingber’s study of tensegrity’s role in disease has helped him forge some unexpected connections. In 2003, he worked with Harvard physics professor Eric Mazur on a nanotechnology project, using a laser to obliterate a minuscule portion of a cell, a few billionths of a meter in size, without affecting surrounding structures. Ingber got involved because he sees the laser as a tool for cutting out a single structure in a living cell to explore its mechanical role. He has also delved into systems biology, a new field that uses computational approaches to explore how molecular parts organize themselves into a system whose properties cannot be predicted by the parts alone. Informed by tensegrity, Ingber hopes to understand how structural, mechanical, chemical and genetic factors combine to govern cell behavior.

He has also helped devise new approaches to tissue engineering, and even posits that tensegrity helps explain the origins of life. Observing that viruses, enzymes, cells, and even small organisms take geodesic forms like hexagons and helices, Ingber suggests that tensegrity is nature’s way of creating strong, stable life forms with minimal expenditure of energy and materials.

“Tensegrity has given me a path that goes deep and broad,” Ingber says. “I believe the greatest value comes when you cross barriers and boundaries and get a new perspective and vantage point. I’m not afraid of following my own path.” Nancy Fliesler