A Diagram of Forces

"The form, then, of any portion of matter, whether it be living or dead, and the changes of form that are apparent in its movements and in its growth, may in all cases alike be described as due to the action of force. In short, the form of an object is a ‘diagram of forces,’ in this sense, at least, that from it we can judge of or deduce the forces that are acting or have acted upon it: in this strict and particular sense, it is a diagram,—in the case of a solid, of the forces that have been impressed upon it when its conformation was produced, together with those that enable it to retain its conformation.

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In an organism, great or small, it is not merely the nature of the motions of the living substance that we must interpret in terms of force … but also the conformation of the organism itself, whose permanence or equilibrium is explained by the interaction or balance of forces."

- D’Arcy Wentworth Thompson (1860 - 1948)
On Growth and Form