This Thursday, February 15, is the birthday of both Galileo Galilee (1564) and Alfred North Whitehead (1861). Since the central concept of each of these thinkers’s thought involved relativity, this is an especially felicitous coincidence and justifies considering their work in relation to each other.

Protagoras (c. 490-420 BC) had said “Man is the measure of all things; of their being and their non-being.” Since then the problem of distinguishing the natures of things as they exist in themselves, absolutely, in reality, from their existence relative to us has been one of the central problems of philosophy. Both Whitehead and Galileo, by admitting a type of relativity in things, aimed at preserving a more important sense in which we could talk about and come to know the absolute nature of reality.

Galileo arrived at the basic laws of terrestrial motion by distinguishing between the motion that an object has in itself and the motion it has relative to an observer. To an observer in space the an object on the surface of the earth is moving in a circle at about 1,000 miles and hour as the earth rotates on its axis. How could we not feel such a motion, asked the opponents of the Copernican Hypothesis that Galileo was trying to answer in his first set of Dialogues. Galileo’s answer was to recognize that this motion was only relative to a stationary observer, and that the real motion of the object of an object was the motion it exhibited in an inertial framework or system of similarly moving objects. All of the objects on a ship traveling together at a constant rate are at rest with respect to each other in a single inertial framework, while to a stationary observer they are in motion. The Galilean Principle of Relativity identifies such inertial frameworks as the place to find the real absolute motions of an object: The results of all physical experiments will be the same (not changing relatively) in all inertial frameworks. Galileo, by recognizing that some of our observations of motion are merely relative, was able to find the real, absolute motions of things.

It turned out, however, that the absolute state of rest or motion of a thing were not among its real, absolute qualities, since the Principle of Relativity seems to make it impossible to distinguish between an absolutely moving inertial framework and one at rest. Einstein’s Special and General theories of Relativity simply extend Galilean Relativity over new domains. Special Relativity allows it to be extended to electromagnetic phenomena, which travel at the speed of light, while the General Theory extends it to gravity and to accelerating frameworks. Einstein, too, was aiming at preserving the absolute character of physical law by recognizing the way in which various of our measurements of it are merely relative to our point of view. It turns out that the concept of simultaneity in time is an artifact of our methods of measurement in the Special Theory, but this does not mean that everything is relative to us. Just the opposite is the real intention of both Galileo’s and Einstein’s theories. By recognizing what is relative we can identify and preserve the domains in which all physical experiments will reveal the real absolute character of physical laws.

Alfred North Whitehead, the great 20th Century Mathematician and Philosopher recognized that the supposed relativistic or idealistic tendencies of these theories contradicted their real intent:

There is a process of nature which is obstinately indifferent to mind. This is why I feel difficulty in assigning to mind, or knowledge, or consciousness any essential role in the flux of fact . . . I cannot persuade myself that relativity in any way weakens this obstinate indifference of nature. It simply shows that there are more various relationships within nature than we had anticipated—no new discovery, for every advance of science adds to the complexity of nature. If Einstein had established the affirmative answer to Pope’s question, “Shall gravitation cease as you go by,” he would have done something to advance the claims of idealism. But all he has done is to make it more difficult for us to compare our watches with those of the inhabitants of Mars. [*]

Whitehead attempted to formulate a metaphysical system, taking process or change as its fundamental category, that took into account the advances of contemporary physics. The fundamental unit of reality is the actual entity or actual occasion, which is itself a drop of becoming or process. Whitehead elevates the Principle of Relativity, in a modified form, into a fundamental metaphysical principle: It is essential to the being of each thing that it be relative to something else. Every drop of becoming or process culminates its being in the way it affects or makes itself part of subsequent events. It is essential to the absolute being of each thing that it become relative to something else. The problem of the external reality and the internal appearance is resolved by making every external reality have an internal process in which other things become relative to it and by making every internal appearance into the real coming to be of a thing in its appropriation of its relatedness to external things: everything has an inside, in which things become relative to it; and everything has an outside through which they become relative to other things. To be is to become for something else.

Just as in Galileo, Whitehead admits the relativity of being to preserve a more fundamental sense in which things have an absolute reality. Things must have a real relativity in order to be relatively real.

[*]The Philosophical Aspects Of The Principle Of Relativity,” Proceedings of the Aristotelian Society, V. 22, 1921-1922, pp, 215-223.