skepticism

a philosophical position that doubts the existence of any reliable criterion of truth. Agnosticism is an extreme form of skepticism, centering on the assertions that nothing in our knowledge corresponds to reality and that genuine knowledge is unattainable in principle.

By stressing the relativity of human knowledge, skepticism played a positive role in the struggle against various forms of dogmatism and in the formulation of a number of the problems of the dialectic of knowledge, although it proved unable to solve them. Skepticism revealed the incomplete, imperfect character of our knowledge and its link with the historical conditions surrounding cognition. However, by transforming this relativity into an absolute, skepticism came to doubt the possibility of verifiable, objective knowledge in general. Proclaiming its denial in principle of any final or definitive judgments, skepticism was, at the same time, constantly obliged to accept certain judgments in practice. The historical role of skepticism in ideological struggles and society has depended on the object of its criticism and the target of its questioning.

In ancient Greek philosophy skepticism was represented by a school that went through three phases of development: early skepticism, which was founded by Pyrrho; the skepticism that took shape at Plato’s Academy under Arcesilaus and Carneades; and late skepticism, represented by Aenesidimus, Agrippa, and Sextus Empiricus. To demonstrate the equal validity of contradictory assertions and the principle of suspending judgment, the classical skeptics used a number of major lines of argument (tropoi), emphasizing the futility of finding a criterion for truth in the realms of sensory knowledge and abstract thought, the disparity between the moral standards of different peoples, and the diversity of religious faiths; expounding how various theories refute each other; and developing the idea that every truth is proved by another, which leads to a vicious circle, to arbitrarily chosen axioms, or to infinite regression. The classical skeptics also used arguments demonstrating that the existence of causality cannot be proved. However, the necessity of acting on one’s decisions forced the classical skeptics to admit that although there may not be a criterion of truth, there is a criterion for practical conduct, which should be based on “rational probability” (Arcesilaus). Classical skepticism urged people to follow the lead of their senses and feelings (to eat when hungry, for example), to follow the laws and customs of their country, and to engage in an occupation (including scholarship). Abandoning a position that tended to distrust sensory perception and thinking, classical skepticism showed a preference for knowledge based on the senses. Thus, classical skepticism was close to empiricism and experimental science. Indeed, its last representatives—Menodatus, Theodas, Sextus Empiricus, and Saturninus—were engaged in the experimental science of medicine.

In the 16th through 18th centuries the term “skepticism” referred to any criticism of religion and dogmatic metaphysics and became a synonym for “freethinking.” Skepticism’s point of departure was rebellion against all “recognized” authority and against the dogmatism of accepted opinions, a call for freedom of thought, and the demand that nothing be accepted on faith. Skeptical ideas were most brilliantly and completely expressed in the works of French thinkers such as Montaigne and P. Bayle. Skepticism provided a foundation for the development of the philosophies of Gassendi, Descartes, Voltaire, and Diderot.

Skepticism took another form in the subjective idealist philosophy of Hume, who questioned the existence of an objective world. In the subsequent development of bourgeois philosophy, agnosticism was more important than skepticism, which became a minor tendency (for example, H. Vaihinger’s philosophy of fictions).