Skepticism

Modern skepticism can trace its origins back as far as ancient Greece. Where today the term can refer to a doctrine or a method of critical inquiry or be regarded as synonymous with scientific investigation, its foundations lie in an epistemol-ogy that denies the possibility of absolute truth and is based instead on the fallibility of the senses and the necessity of reason to better understand why we see what we do. Its opposing philosophy is that of dogmatism, which maintains that some truths or conclusions are absolute and beyond criticism.

In the 5th century BCE, the philosopher Democritus wrote that two forms of knowledge exist, “one legitimate, one bastard.” The “bastard” knowledge was said to involve the five senses, but [Page 796]the other form of knowledge took over where these proved inadequate.

The concept of “fallible perception” formed the basis of a number of philosophical schools in the ancient world and is often referred to as sensory skepticism. A group of wandering teachers called the Sophists preached that knowledge was relative and that what we take for truth is only the better reasoned of any collection of statements. The sophist Gorgia based his reasoning on the fact that the perception of an event could vary between individuals or even vary with the same individual on different occasions. Because knowledge was dependent on our perception of reality, it was impossible to distinguish those observations that reflected the truth.

Another famous sophist by the name of Protagoras described man as “the measure of all things”; in other words, by its very nature, knowledge cannot be distinguished from our perception of it. By extension, because perception is a subjective experience, knowledge also cannot be objective by nature.

Philosophical skepticism is often referred to as “Pyrrhonism,” a school of thought established by Aenesidemus and named after the 4th-century-BCE philosopher Pyrrho. It was maintained that personal peace and tranquility could be found only once the individual realized that it was impossible to know anything with absolute certainty. So extreme was this school's teachings that not even its core belief was exempt from its own philosophy, producing an interesting paradox. The aim of Pyrrhonism was to achieve a state of “ataraxia”—freedom from anxiety—where the individual could focus on things only as they appear to be and not dwell on possibilities that can never be proven one way or another.

The 3rd-century-CE physician and philosopher Sextus Empiricus wrote extensively on the nature of philosophical skepticism; however, he was himself optimistic on the possibility of absolute knowledge under certain circumstances. Since dogmatic skepticism was a contradiction in terms, Sextus maintained that he neither believed in absolute knowledge nor in its impossibility. Rather, he advocated that skepticism should involve questioning of the nature of subjective perception, of the objective world, and of the relationship between them. Doubt can be introduced on any of these levels.