Hold questions and comments until the end, please, so we can be sure to get through all of what I have to say. As we go along, make a note of any discussion-worthy points that occur to you, so you won't forget to raise them. But if you have a brief and specific request for clarification of something I say--you don't hear, or don't understand, something I say- please interrupt boldly.

Brief formula: nobody knows anything; perhaps: nobody can know anything--knowledge, certainty, is impossible (not quite the ancient position)
Global vs. local skepticism (e.g., religion, ethics)
Ontological skepticism (concerns the existence of things or the truth of propositions about them--neither affirms nor denies) vs. epistemological skepticism (concerns our ability to know things--"best" skepticism neither affirms nor denies their knowability)

Etymology (note that there was an ancient school or movement whose members actually called themselves "Skeptics" (or the cognate Greek term)

skepsis--examination, reflection, consideration
skeptomai--to look carefully at, view, examine, consider, inquire
skeptikos--inquiring (one)
dogma--opinion, firm belief, that which one thinks true

Problems with the early record--I'll tend to blur some possible distinctions between positions, since those positions are themselves fuzzy. Why? All reconstruction necessarily tentative.

History of skepticism‹outline (Hellenistic = from death of Alexander (323) to Roman annexation of Egypt (30 BCE))

Presocratics (Xenophanes (c. 560-470), Parmenides (c. 515-450), Democritus (c. 460-370), et al.)
Sophists--Gorgias (c. 483-376), Protagoras (c. 490-420), et al.
Socrates (470-399)--refute error rather than impart knowledge
Pyrrho (c. 360-270)
The Academy--(skeptical c. 280-80, after which it reverted to Platonic dogmatism)
Arcesilaus (c. 317-242)
Carneades (c. 215-130)
Aenesidemus (1st c. BCE--left Academy for Alexandria to revive an "authentic" Pyrrhonism; reduced the arguments for Skepticism to ten modes)
Sextus Empiricus (c. 150-225)--Outlines of Pyrrhonism (physician; main source for skeptical principles and arguments)

1560's: Latin translation of OutlinesŠ
Michel de Montaigne (1533-92) -- "Defense of Raymond Sebond" (1580)
René Descartes (1596-1650) -- Meditations on First Philosophy (1640)
David Hume (1711-1776) -- Enquiry Concerning Human Understanding (1748)

Ancient Skepticism in general, and Pyrrhonism in particular

An attack not on all belief, but on Dogmatists: Those who subscribe todogmas‹doctrines or theories, accounts of the way things really are; who explain why things seem as they do by reference to something that is not evident: the "essences" or "natures" of things behind appearances. Among the objects of their criticism: Platonists, and Stoics ("we directly apprehend some truths; impressions that seem to one to be irresistible and indubitable must be true").

The Skeptics make no statements of fact; what appears to be a statement of fact expresses instead what seems or appears to be the case. The Skeptics assent to compelling impressions. They used arguments, especially those appealing to the relativity of judgment--the fallibility of perception (senses unreliable standards of truth), disagreement of experts, etc.

But the force or credibility of an argument is just our involuntary inclination one way or the other. (Even such Skeptical claims as "All things are relative" express a seeming-to-be; they may turn out to be wrong (in the sense to be clarified).)

Any doctrine has as much to be said for as against it.  I don't affirm that the arguments actually are of equal strength; it just seems to me now that they are. And I don't judge the issue to be undecidable: for all I know, I might come across a decisive argument. (But if considerations to now seem to favor one side, further "evidence" may turn up that will incline me the other way.) The consistent Skeptic neither affirms nor denies that certainty is possible. But the general thrust is that truth is ungraspableŠat least the truth about the real natures of things. (Hierarchy of knowledge levels implicit; avoid a self-referential paradox in Socrates' "I know only that I know nothing". Means "I find myself determined to believe (at level 2) that I am not committed to any (level 1) beliefs . . . though these may change.")

From Pyrrho on, Skepticism was thought to provide the basis for a whole way of life. Puzzle > mental disturbance, distress > investigation, inquiry > discovery of apparently balanced plausibility > suspension of judgment > tranquility, peace of mind. (">" is causal; "x > y" means "I find that y follows upon x". For example, the suspension of judgment is not the result of rational deliberation on opposing arguments, but is just the effect of frustrated inquiries into the natures of things.) Tranquility, peace of mind was the goal of the other main Hellenistic schools of philosophy--Stoics and Epicureans; but they sought it through knowledge.

Skepticism after Sextus

Philosophical Skepticism was strong enough by the end of the 4th c. CE to merit attack by Augustine (354-430). Not much interest thereafter, until the publication in the 1560's of a Latin translation of Pyrrho's Outlines of Pyrrhonism revived interest. Then Montaigne's skeptical writings in French stimulated further interest, and influenced many later writers. These appeared as two other things were going on: the religious controversies of the Reformation (skepticism actually advanced in support of faith in the Roman Catholic position), and the impact of the new science on our everyday view of the world.

Descartes regarded the refutation of skepticism (in our initial sense) as a primary goal. But his method has been aptly called "methodological skepticism". He begins his Meditations on First Philosophy with an initially successful attempt to doubt everything, in which he reviews a number of the standard arguments against the unreliability of the senses, and even gives an argument for the unreliability of mathematical proof. (I could give you that argument in the discussion period if you're interested.)

Hume was one of the most thorough and thoughtful of the modern Skeptics. I particularly recommend to you his Enquiry Concerning Human Understanding, the first and last chapters of which--"Of the Different Species of Philosophy" and "Of the Academical or Skeptical Philosophy"- locate his own position in its historical and philosophical context. His argument are careful and often subtle. The bottom line is this: we can have no certainty about matters of fact; we can confidently know only truths of logic ("All red fire-engines are red") and mathematics ("2 + 5 = 7"), which are empty or vacuous: they give us no information about the world. As for claims about the world, we are entitled to more or less confidence in proportion to the degree of evidence in their favor. Nothing justifies our general beliefs about the world. But we are conditioned by the repetition of patterns in our experience to expect past regularities to continue.

The Logical Positivists, from the Vienna Circle of the 1920' s and 30's on, developed such ideas of Hume and others, merging them with the science of the 20th century to yield a sophisticated theory of knowledge and philosophy of science. Similar skeptical themes run throughout Positivism, particularly in its broad attack on metaphysics and philosophical pretensions.

Copyright (©) 2003, William A. Wisdom