Measurement
Measurement is the identification of a quantitative relationship, established by relating the thing measured to a standard that serves as a unit. Objectivism gives it a role beyond the sciences: the same relationship that lets a length be stated in metres is what makes concept formation possible, through measurement omission.
“Measurement is the identification of a relationship — a quantitative relationship established by means of a standard that serves as a unit.”
~ Ayn Rand, "Cognition and Measurement", Introduction to Objectivist Epistemology
What measuring does
To say that a table is nine feet long is not to report an intrinsic property of the table. It is to state a relationship between the table and a foot: the table stands to that unit in a ratio of nine to one.
Two things follow, and both matter for the epistemology.
- The unit is chosen; the relationship is not. Feet or metres is a decision. Whether the table is longer than the door is not. This is the pattern Objectivism finds throughout human cognition: the form is contributed by the measurer, the content by reality. See Objectivity.
- Every chain of measurement ends in perception. A metre is defined today in terms of the speed of light, which is established by instruments, which are read by someone looking at them. However long the chain, the standard is ultimately something a person can perceive directly. A measurement whose chain does not terminate there has measured nothing. See Perception and Senses.
The purpose Rand assigned to measurement is the expansion of consciousness beyond the perceptual range: it relates what a man cannot directly grasp — the distance to a star, the mass of an atom — to something he can, by a series of steps each of which he can follow.
Beyond quantity
Measurement in the ordinary sense applies to attributes with a scale: length, weight, temperature, frequency. Rand extended the notion further, to any characteristic that varies in degree along a dimension, including ones nobody quantifies numerically.
Shades of a colour differ in hue and intensity. Two people's courage differs in degree. In neither case does anyone assign numbers, but in both there is a "more and less" that can be ordered, and that ordering is what the analysis requires. Rand called measurements of this kind teleological when the standard is a purpose rather than a physical unit, and treated the extension as necessary to cover concepts of value and of consciousness as well as concepts of physical things.
This is why the theory of concepts can be stated in terms of measurement without claiming that men measure anything when they think.
The link to concepts
Similarity, on Rand's account, is the relationship between existents that possess the same characteristic in different measure or degree. That definition is only available once measurement is understood, and it is what makes concept formation a definite process rather than a description of noticing.
Forming a concept retains the characteristic and omits the particular measurements, on the principle that they must exist in some quantity but may exist in any. See Measurement omission and Conceptual Common Denominator.
Common misunderstandings
- That measurement requires numbers. Numbers are the most precise form. Ordering by more and less is measurement in the sense the theory needs.
- That the choice of unit makes measurement subjective. Choosing a unit is like choosing a language: it settles how the fact will be stated, not what the fact is. A table nine feet long is 2.74 metres long, and both statements report one relationship.
- That measurement omission means measuring and then discarding. No measurements are taken at any point in forming a concept. The claim is that the characteristics are measurable — that they vary along a dimension — which is what makes the omission meaningful.
See also
- Measurement omission · Unit · Concept · Concept formation
- Conceptual Common Denominator · Crow-epistemology · Unit-economy
- Perception · Senses · Objectivity · Science
- Existents · Identity · Epistemology
Discussion
References
- Rand, Ayn. "Cognition and Measurement", Introduction to Objectivist Epistemology. The Objectivist, 1967.
- Peikoff, Leonard. Objectivism: The Philosophy of Ayn Rand, chapter 3.
| Epistemology Topics |
|---|
| Senses | Consciousness | Volition | Concepts: Unit, Concept-Formation |
| Objectivity | Knowledge: Context, Hierarchy | Reason: Certainty, Truth, the Arbitrary | Emotions |