Return to Skepticism
The crusading skepticism of the modern era; the mounting attack on absolutes, certainty, reason itself; the insistence that firm convictions are a disease and that compromise in any dispute is men’s only recourse—all this, in significant part, is an outgrowth of Descartes’ basic approach to philosophy. To reclaim the self-confidence of man’s mind, the first modern to refute is Kant (see [Introduction to Objectivist Epistemology]); the second is Descartes.
Observe that Descartes starts his system by using “error” and its synonyms or derivatives as “stolen concepts.”
Men have been wrong, and therefore, he implies, they can never know what is right. But if they cannot, how did they ever discover that they were wrong? How can one form such concepts as “mistake” or “error” while wholly ignorant of what is correct? “Error” signifies a departure from truth; the concept of “error” logically presupposes that one has already grasped some truth. If truth were unknowable, as Descartes implies, the idea of a departure from it would be meaningless.
The same point applies to concepts denoting specific forms of error. If we cannot ever be certain that an argument is logically valid, if validity is unknowable, then the concept of “invalid” reasoning is impossible to reach or apply. If we cannot ever know that a man is sane, then the concept of “insanity” is impossible to form or define. If we cannot recognize the state of being awake, then we cannot recognize or conceptualize a state of not being awake (such as dreaming). If man cannot grasp X, then “non-X” stands for nothing.
Fallibility does not make knowledge impossible. Knowledge is what makes possible the discovery of fallibility.