Clear-cut nomenclature is essential to clear thought.

B. H. Liddell Hart, Strategy

The truth or falsehood of all man's conclusions, inferences, thought and knowledge rests on the truth or falsehood of his definitions.

Ayn Rand

Art is the selective re-creation of reality according to an artist's metaphysical value-judgements.

Ayn Rand, The Romantic Manifesto"The Psycho-Epistemology of Art"

Biology is the science that studies living organisms.

Andrew Layman

A definition is a statement the identifies the nature of the units subsumed under a concept.

Ayn Rand, Introduction to Objectivist Epistemology"Definitions"

Education is the systematic training of the conceptual faculty of the young by means of supplying in essentials both its content and method.

Leonard Peikoff, Teaching Johnny to Think[extemporaneous, uneditted formulation]

History is the science that studies what man has done, identifying fundamental causes.

Eric Daniels

Life is a process of self-sustaining and self-generated action.

Ayn Rand, Atlas ShruggedGalt's speech.

Literature is the branch of art which recreates reality by means of language.

Ayn Rand, The Romantic Manifesto"Art and Cognition"

Natural Science
Natural Science is the branch of science that studies all phenomena except those dependent on the action of man's conceptual consciousness.

Andrew Layman

Philosophy is the science that studies the fundamental nature of existence, of man and of man's relation to existence.

Ayn Rand, Philosophy: Who Needs It

Science is the systematic knowledge gained by use of reason based on observation.

Leonard Peikoff, Objectivism: The Philosophy of Ayn Rand"Virtue as Practical"

War is armed conflict among men, in which a political unit attempts to achieve objectives by means of organized force against other men.

Andrew Layman

Vitruvian Man, by Leonardo da Vinci

Vitruvian Man, by Leonardo da Vinci