Monthly Archives: April 2010

Organism vs. Mechanism: Science at the Lagrangian Divide

The Lagrangian equations are a powerful set of differential expressions describing the motion of a complex system.  With one equation for each component of the system, they would seem to offer a powerful expression of the relation of part to whole.

They are, however, seriously ambivalent: they can be read in either of two opposite ways. They present, then, a stark problem for the art of interpretation, the highest branch of rhetoric, as it comes from Augustine to Bacon and Newton.  The same statement becomes a watershed; it may belong to one world, or its opposite – but not both.  Each is a containing frame, within which we picture, and live, our lives

Read in one way – the way most common today – they are seen as derived from Newton’s laws of motion, and thus adding nothing fundamentally new. From this perspective, they merely rephrase Newton in terms of the concept of energy, a mathematical convenience in certain circumstances but making no fundamental change in our understanding of the natural world. In this interpretation, they express what we today call mechanism, which sees the motion of any system as the mere aggregation of the motions of its individual parts. Causality flows upward; motions of the parts explain the motion of the whole.

Seen from the other side of the Lagrangian watershed, however, the same equations express a world of a totally different sort. Here, the same equations are derived from the Principle of Least Action – a concept which readers may recognize as one of the recurring themes of this website.  The system itself as a whole, described in terms of potential and kinetic energy, becomes the primary reality and the source of the motions of the parts. Causality arises from the  interplay of these energies, and flows in the reverse direction, from whole to part.

Within the world of mechanism – the first interpretation – there is no place for goalor purpose. These are concepts considered far too vague to meet the standard of objectivity, the signature of modern science.

Remarkably, however, Least Action reconciles purpose with quantitative objectivity. By means of the mathematical technique of variation, which considers all possible paths, this principle seeks the optimum path by which potential energy may, over he whole course of any natural motion, be transformed to kinetic. In this interpretation of Lagrange, then, our world-view is transformed. Science itself, while remaining strictly objective and quantitative, becomes at the same time goal-oriented – all at once!

More than this, however, science on the Least Action side of the Lagrangian divide becomes, at last, fundamentally organic. This arises from a further, crucial feature of Least Action: if a system as a whole moves in such a way as to minimize action,so also will, within the bounds of external constraints, every part of that system. The goal which belongs primarily to the whole, is pervasive: it is shared by every part.

It was important in stating this principle to add “within given constraints”, because a rigid part of a man-made machine has few options. By contrast, the myriad components of a leaf, or of a cell or enzyme within the system of a leaf, navigate among unimaginable options toward the common goal of turning sunlight into life, over the season of the leaf, the life of the tree, or the evolution of photosynthesis on earth.

It is this community of purpose, nested and shared, which renders a system trulyorganic – a living being, something fundamentally beyond any bio-molecular mechanism, however intricate.

It is hardly necessary to add that it is this sense of nested purpose and shared membership in natural communities which has been so lacking during the long reign of mechanism. Our so strongly-held worldview has diverted us from that other option, which has nonetheless long formed a strong alternative flow of thought and practice in science, mathematics, politics and the arts. Now in many ways, not least the earth’s biosphere itself, the demand is upon us to recognize that we do have an option of immense importance. Viewing this whole scene now, we might say, from the Lagrangian ridge-line itself, with both worldviews clearly in view, our task is truly dialectical: leaving none of the insights of the past behind, we are in a position to move forward into a new, far richer and wiser world.

That new world-view, which has appeared here as a richer interpretation of Lagrange’s equations, is the ongoing theme of this website – always with an eye to Maxwell’s turn to Lagrange as mathematical vehicle for the launch of his concept of the electromagnetic field, paradigm, if ever there was one, of that whole system of which we have been speaking.

[A brief introcution to the Principle of Least Action is given in my lecture, “The Dialectical Laboratory” .

It is important to add that in this thumbnail sketch, many nuances of the application of Least Action have been left without mention]

“There’s no Space in Euclid!” or Euclid’s Rhetoric

“There’s no ‘space’ in Euclid!”
I remember vividly the moment when a talented young tutor at St. John’s College in Annapolis, Maryland, came careening down the stairway our old library, unable to contain this startling realization. As a new tutor at the “Great Books College”, he had likely been assigned to teach a class in the subject he knew least, and was as a result making his first encounter with Euclid’s Elements in the company of a class of first-year students – an experience as fresh and surprising to him as  to his student fellow-readers.

Euclid writes in a style we no longer expect of mathematicians: simple, confident, almost buoyant. In the scale of rhetorical possibilities, Euclid’s is the style Aristotle calls “simple”. His figures stand upright and firm, on their own: they have no dependence on a “space” in which to be.

Reading the classics in this unscholarly way, as if they had been written for us, is an experience filled with such surprises; as myself a student at the College at the moment of this proclamation, I recognized the experience: the same revelation had struck me not long before. Euclid’s idea of geometry is not what we moderns have been led to expect!

One aspect of this dis-conformity between Euclid’s world and our modern expectations is this troubling absence in Euclid’s mind of any notion of “space”. Euclidean figures, all the way to the great regular solids in which the thirteen books of his Elements culminate, are organic webs of relationships, each standing whole before the mind’s eye, increasingly vivid  as the plot  thickens. Our relationship with them is direct and immediate: they are not “in” anything!

Similarly, Euclid never proves anything, in our modern sense. His style is strikingly at odds with the ways of today’s formalism, which tends to bind the mind in chains of consequence, rather than liberating it. Euclid leads us to contemplate the figure which evolves as the demonstration (epidexis, a showing) unfolds. We construct the figures as we go along, and take well-deserved satisfaction, as they unfold, in our workmanship.

At each step in the course of a demonstration we are tacitly invited to lend assent. There is, on the other hand, nothing as it might seem, loose or casual about all this. Euclid relies at each step on a very real power of intellectual intuition – on our human ability to discern truth when we see it. Euclid as author is, at the same time, our teacher. Under his guidance we develop confidence and soon find ourselves taking delight in the exercise of new-found power of geometrical insight. Skeptics today will accuse us of self-deception, and Euclid, of naivete. But we and Euclid may stand if we wish by our own agreement, when we confirm a geometrical truth.

An illustration from Euclid: Book 1-PropositionsA striking example of Euclid’s method at work would not be far to seek: the first words of his Elements make a strong demand on our visual intuition. We are asked to construct an equilateral triangle:  (please excuse the informality of these images derived from my aging copy of Euclid!)

The procedure is very simple.  We begin with the straight line AB:

And on it at point A draw a circle ACB of radius AB:

(Point C is here no more than a label, not yet specified, to identify the circle in question.)

Similarly, at point B, we construct a second circle. ACE of the same radius:

(“C” is still functioning as a label, not yet located.)

But now, Euclid begins the final stage of the construction, with no hint of apology or explanation, by giving the mysterious “point C” a specific location, and a crucial function: “from the point C, at which the circles  cut one another ….”.

We stop to catch our breath!  Point C has now been specified, without ceremony or justification.  How do we know that it exists – that the circles do indeed intersect?  Euclid’s answer is simple: we know it, because we see it, in our mind’s eye – and of course we never really doubted.

We proceed to draw the sides, complete the figure and carry our new triangle with us, a secure foundation on which the great structure of the Elements will rest.

This is to be Euclid’s style throughout: even first principles are not legislated, but offered for our agreement. They are things asked of us or postulated, as questions (AITIAE) or proposals – and the rhetoric of the Elements will be consistent throughout.

Similarly, when we pause at the close of a long stretch of reasoning, to review the steps we have just passed through, this is not a matter of mere logical bookkeeping.  It is, rather, clearing the way to that moment of commanding insight, in which we say, in the spirit we now think of as that of Gestalt, “Aha!”I see!” And indeed, we do.

This is the rhetoric of Euclid, which so shapes our path that the we are led to see.  What department of mind is this, which Euclid is invoking?  I’m sure he would be in easy agreement with Plato, that while the logical mind grinds away at syllogisms, another, higher department of mind sees truth, and says “yes” to an argument not because it is bound by chains of syllogism to do so, but because it can view truth directly, and know it for what it is.  Plato calls this higher, defining power of mind NOUS, and as his dialogue Theaetetus makes clear, mathematics, practised in this mode, is crucial preparation for an approach to the highest things.

I have been drawing attention to Euclid’s rhetoric, but just as the rhetoric of Plato’s dialogues is essentially philosophic – skillfully leading the respondent to a question which is philosophic because it leads logic to an impasse and thus invites a higher end– so Euclid’s rhetoric leads as well to an end beyond the familiar realm of figure. I propose we should identify this further mode, having to do with the matters of plot and character, as Euclid’s poetic. It will be the topic of a separate posting, to follow soon on the heels of this one.

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Footnote Concerning Other Geometries

Followers of this website may find it surprising that on the one hand I praise Euclid for his clarity about a three-dimensional world – while on the other, I announce a new expedition on this very website into a world of four dimensions. I even claim that we will be experiencing an intuitive sense of relationships in a four-dimensional world. What sort of contradiction is this?

My own proposition is this: Euclid invokes the power of geometrical intuition, but he does not set bounds to it. We have the ability to keep track of the agreements we make in signing-on to sets of postulate belonging to worlds quite different from Euclid’s: we may very well learn to see in our minds’ eyes rooms with four directions at each corner, or left shoes turning readily into right – powers of the visual imagination we have not yet learned to use. This website will post images from this project as unfolds. Stay tuned, and feel free to share any comments you may have