objectivist epistemology notes

These are notes fomr “Introduction to Objectivist Epistemology” by Ayn Rand. This is great work on how we learn and form concepts based on everyday experiences.

Cognition and Measurement

Consciousness, as a state of awareness, is not a passive state, but an active process that consists of two essentials: differentiation and integration.

Differentiation of inputs into useful groups and integration of examples in those groups to form a concept that is representative of that group.

… an infant’s sensory experience is an undifferentiated chaos.
This is useful to remember as where does the learning start – at a state of chaos.

The building-block of man’s knowledge is the concept of an “existent” – of something that exists. … the data which are later to be integrated by that concept.

A sensation is a sensation of something, as distinguished from the nothing of the preceding and succeeding moments. A sensation does not tell man what exists, but only that it exists.

The ability to regard entities as units is man’s distinctive method of cognition,…

A unit is an existent regarded as a separate member of a group of two or more similar members.

Note that the concept “unit” involves an act of consciousness (a selective focus, a certain way of regarding things)

Measurement is the identification of a relationship – a quantitative relationship established by means of a standard that serves as a unit.

The requirements of a standard of measurement are: that it represents the appropriate attribute, that it be easily perceivable by man and that, once chosen, it remains immutable and absolute whenever used.

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.

Man is the measure of all things

We need to take into account the fact that the world is perceived by an AI and should be expressed internally by the internal measures that have meaning for that AI.


A concept is a mental integration of two or more units which are isolated according to a specific characteristic(s) and united by a specific definition.

The act of isolation involved is a process of abstraction: i.e., a selective mental focus that takes out or separates a certain aspect of reality from all others (e.g., isolates a certain attribute from the entities possessing it, or a certain action from the entities performing it, etc.). The uniting involved is not a mere sum, but an integration, i.e., a blending of the units into a single, new mental entity which is used thereafter as a single unit of thought (but which can be broken into its component units whenever required).

IN order to be used as a single unit, the enormous sum integrated by a concept has to be given the form of a single, specific, perceptual concrete, which will differentiate it from all other concretes and form all other concepts. This is the function performed by language. Language is a code of visual-auditory symbols that serves the psycho-epistemological function of converting concepts into the mental equivalent of concretes. Language is the exclusive domain and tool of concepts. Every word we use is a symbol that denotes a concept, i.e., that stands for an unlimited number of concretes of a certain kind.

Words transform concepts into (mental) entities; definitions provide them with identity.

In order to form the concept “length,” the child’s mind retains the attribute and omits its particular measurement. Length must exist in some quantity, but may exist in any quantity.