Answer: "Reason is the faculty which… identifies and integrates the material provided by man's senses. Reason integrates man's perceptions by means of forming abstractions or conceptions, thus raising man's knowledge from the perceptual level, which he shares with animals, to the conceptual level, which he alone can reach. The method which reason employs in this process is logic—and logic is the art of non-contradictory identification."
— Ayn Rand "Faith and Force: The Destroyers of the Modern World," in Philosophy, Who Needs It? p. 62.
holds that all human knowledge is reached through reason
, the human mental faculty of understanding the world abstractly and logically. Aristotle called man "the rational animal" because it is the faculty of reason that most distinguishes humans from other creatures. But we do not reason automatically. We are beings of free will and we are fallible. This is why we need the science of knowledge—epistemology—to teach us what knowledge is and how to achieve it.
The basis of our knowledge is the awareness we have through our physical senses. We see reality, hear it, taste it, smell it, feel it through touch. As babies, we discover the world through our senses. As our mental abilities develop, we become able to recall memories and we can form images in our minds.
Objectivism holds that all human knowledge is reached through reason .
Other animals are also capable of perception and memory. What most obviously sets humans apart is our bountiful use of language. The difference is more fundamental, though: at root, language is a means of formulating and expressing abstract thoughts.
are ideas that correspond to an unlimited number of things at once. When you say or think "horse," for example, your mind focuses on an idea—a concept— that refers to all the horses that ever have been or will be. Concepts allow us to consider the past and the future, things that are, things that might be, and even things that can't be. Using concepts together, we can formulate general principles, like the laws of nature, that apply to many situations.
The ability to grasp reality in the form of abstract concepts and principles is the essence of reason as a human capacity
. But thinking abstractly is often a difficult process and each person must undertake it for himself in the solitude of his own mind. Because abstract thinking is not automatic, people can easily make mistakes and end up believing in false ideas. The only way to ensure the objectivity of one's thinking is to use a deliberate logical method.
"Logic is the art of non-contradictory identification," wrote Ayn Rand
. Because there are no contradictions in reality, two ideas that contradict each other cannot both be true; and any idea that contradicts the facts we can observe through our senses is necessarily false. Logic gives us standards we can use to easily judge whether an argument makes sense. The scientific method is an advanced form of logical reasoning. Through it, reason has unlocked the secrets of nature and made our industrial civilization, with all its wealth and comforts, possible.
Objectivists defend the efficacy of reason against all critics. Skeptics say that because we are fallible, we must doubt all our beliefs. But this claim is a self-contradiction: the skeptic is claiming certainty at least for his belief in our fallibility. Religious mystics often claim that God or the supernatural is so different from everything we know that it is beyond reason's ability to understand. But since whatever exists has identity, i.e. definite and delimited properties, it is always possible to contrast it with other things, conceptualize it, establish standards of measurement, and thereby begin to reason about it. At a time when mathematicians explore the properties that even infinite spaces and processes must have, it underestimates the human mind to think it incapable of plumbing deep or complex phenomena.
Anyone who claims insights that do not derive from sensory evidence and logical reasoning is, in effect, asking you to abuse your mind. Someone who claims, skeptically, that no real knowledge is possible is asking you to abandon your mind entirely. Objectivism
holds that it is possible to be certain of a conclusion, and that there is such a thing as truth. But being certain depends on scrupulously following a logical, objective process of reasoning, because it is only that kind of thinking that allows us to formulate true ideas. To be objective, people must know how to define the terms they use (so they know what they mean), base their conclusions on observable facts (so their beliefs are anchored in reality) and employ the principles of logic (so that they can reliably reach sound conclusions).