Lawrence Joseph Henderson

"... More explicitly than ever before the modern principles of physical science seem to compel us to recognized absolute mechanical necessity in all things. We may not understand organic regulations, or organic evolution, or the origin of life; in fact we are still unable with the necessary clearness to represent to ourselves the structure of a cell; yet theses are at least phenomena. As phenomena they are subject to the two laws of thermodynamics. For the laws of conservation and degradation of energy have long since supplanted Leibniz's rudimentary idea of the conservation of ', as the ground of our conception of necessary causation."

"It is in proportion to our success or failure in conceiving facts simply that sciences are abstract or concrete, rational or descriptive. In these respects the contrast is great between the physical and the biological sciences. The figure of the earth, its path about the sun, and its relations to the other planets are readily conceivable in a first approximation as simple; but the forms of life seem complex, their activities manifold, and the concatenations interminable. Therefore, unlike celestial mechanics, the science of biology, which is the record of efforts accurately to describe and clearly to understand living things, is chiefly a science descriptive of concrete fact. It bears little resemblance to the more perfect science and as yet is in no danger of a relativist revolution. It has never attained, perhaps, as some have argued, it can never in any respect achieve and should not strive for the abstractness, the elegance, and the simplicity which are the mark of the classical epoch of many the physical sciences and the ideal of those who follow Newton and Willard Gibbs."

"Four centuries ago, Machiavelli was thinking of certain great problems of human society and writing two famous books. In so doing he reached scientific generalizations about the influence of the sentiments upon the actions of men and, through these actions, upon the fate of human societies. As a whole, these conclusions stand; but from this great and ingenious work of Machiavelli's almost no developments have followed. The science of statecraft and of the influence of the sentiments upon human behavior is little different to-day from what it was in in the 16th century."