The Epistemic Role of Measurement

What measurement and concept formation in general allows man to do is to bypass the crow. Namely, it is said that a crow is able to at one time hold only four or five units in it’s head at once—i.e. it can easily tell the difference between four and five objects of awareness, but not between 100 and 101. We call this limit “the crow,” and it exists for every consciousness, because A is A and you therefore can’t have an unlimited consciousness—i.e. a consciousness that can hold infinite units within direct apprehension at the same time. The way that a human overcomes this is by summing up an infinity of possible concrete permutations within a single concept—he is able to count up how many men there are in a room, count again and see that the number has increased by one.

The epistemological purpose of measurement is best approached through an example. Consider the fact that the distance between the earth and the moon is 240,000 miles. No creature can perceive so vast a distance; to an animal, accordingly, it is unknowable and unfathomable. Yet man has no difficulty in grasping (and now even traversing) it. What makes this cognitive feat possible is the human method of establishing relationships to concretes we can directly perceive. We cannot perceive 240,000 miles, but that distance is expressed in miles, and a mile is reducible to a certain number of feet, and a foot is: this (I am pointing to a ruler). It works in the other direction also. A certain chemical reaction, a scientist reports, takes place in 4.6 milliseconds. A thousandth of a second is too small to be within the range of perceptual awareness. Yet by relating this time interval, as a fraction, to one that we can apprehend directly, we can grasp and deal with it as well. In both directions, Ayn Rand holds, and in regard to countless attributes, the

purpose of measurement is to expand the range of man’s consciousness, of his knowledge, beyond the perceptual level: beyond the direct power of his senses and the immediate concretes of any given moment. […]

The process of measurement is a process of integrating an unlimited scale of knowledge to man’s limited perceptual experience–a process of making the universe knowable by bringing it within the range of man’s consciousness, by establishing its relationship to man.¹