Critique of Moore’s objections to skepticism
G.E. Moore attempted his own refutation of skepticism, toward which On Certainty was inspired and directed to a large degree. Moore wrote several articles in challenging skepticism, including A Defense of Common Sense, Four Forms of Skepticism, and Proof of an External World. His general objection can be summarized by taking the skeptics’ modus ponens and using the same conditional to form a modus tollens argument. Using the same example as earlier, Moore would argue,
- If I can not distinguish between dreaming and being awake, then I can not be sure I have a body.
- I am sure I have a body.
- Therefore, I can distinguish between dreaming and being awake.
Though Moore is correct in challenging that doubting such basic claims is unreasonable, Wittgenstein suggests that Moore still fails to answer the skeptic because Moore’s claim that he knows he has a hand is subject to the question of how he knows- bringing him back to the beginning of the argument with the skeptics.
Furthermore, Wittgenstein accepts Moore’s propositions, but not his subjective assurance that they are true. The meaning of the phrase “I know that…” is initially explained in demonstrating the insufficiency of Moore’s arguments against skepticism. Firstly, “P” can not be properly inferred from someone’s statement, “I know P.” While “P” can be inferred from “he knows P,” this requires justification (13, 14). The assurance “I know” is insufficient to demonstrate that no mistake is possible (15). Besides the contextual exceptions of the usage of “I know” (“I can not be wrong,” “I thought I knew,” etc.), the phrase is insignificant; if one actually knows that something is the case, then it is the case.
He then proceeds to argue, “Moore’s mistake lies in this – countering the assertion that one cannot know that, by saying ‘I do know it’” (521). Since skepticism is nonsense, as Wittgenstein establishes, it need not and can not be refuted by a counter-example. Moore, actually, commits the same error as the skeptic by treating logic (which is founded on those basic propositions) as empirical statements requiring proof.
Wittgenstein makes a general statement about Moore’s argument, which also happens to be a repetition of one of the most important themes of On Certainty:
When Moore says he knows such and such, he is really enumerating a lot of empirical propositions which we affirm without special testing; propositions, that is, which have a peculiar logical role in the system of our empirical propositions (136).
Moore did not recognize this, instead attempting to answer the skeptic on epistemological grounds. Wittgenstein construes this attempt as not only one to refute skepticism, but to provide a list of “certain propositions… excluded from doubt” in a “logic-book” (625). According to Wittgenstein’s approach, however, the proper response to skepticism is not to delineate particular empirical facts, which can be ultimately undermined, to show certainty; rather, it is to assert that one must be sure of facts that allow one to think about other facts.
Wittgenstein was the ultimate anti-skeptic
To return to the Tractatus once more, even there Wittgenstein’s anti-skeptic stance was developed in key ways: “Doubt can exist only where a question exists, a question only where an answer exists, and an answer only where something can be said.” There are some things which must be taken without question in order for one to function as a human being. Some may mistake this as a kind of fideism, but it is, in fact, a necessity for thought and goal-directed action.
Wittgenstein aptly undermines the meaningfulness of skepticism by showing that its arguments depend in some way on what it sets out to disprove. The philosophical nature of the skeptics’ arguments is dependent on the kinds of necessary contextual statements embodied by Moore-type propositions. There is a dependency on some certainty in belief necessary for the use of language: “if you are not certain of any fact, you cannot be certain of the meaning of your words either” (114). Further, communication between two people – employed by skeptical philosophers, clearly – can not occur without some common ground. The most basic propositions like, “I have a body” or “here is a hand,” when doubted, wholly eliminate that common ground. Without certainty of rules of a language-game, which depend on commonality founded in propositions like “here is a hand,” all ideas and the meanings of all communication must be doubted, including those of skepticism. Skepticism is thus a self-detonating position.
Logic and experience can only be responsible for themselves, as there exist no other tools for evaluating them. Moore failed to call attention to the fact that skepticism uses an argument against logic and experience that requires logic and experience. Instead, he attempted to “play the skeptic’s game” by attempting to show examples that conform to the skeptics’ super-rational definition of knowledge, an attempt invariably doomed to failure. To doubt, one must have a foundation from which to doubt. He must have a position of truth to which he can retreat when he spots a falsehood. The skeptic wishes to criticize this position and any such positions, while still maintaining a meaningful existence as a human being who uses language and takes action. As On Certainty shows, those two desires are mutually incompatible. For all intents and purposes—intents and purposes, whose existences depend on human language and action—skepticism is left meaningless.
[1] Subsequent citations of this form refer to the numbered notes in the edition of On Certainty edited by G.E.M Anscombe and G.H. Von Wright, translated by G.E.M. Anscombe and Denis Paul.
[2] Tractatus Logico-Philosophicus, 4.121
[3] Tractatus, 3.031
[4] Note that Wittgenstein clarifies that there is no “sharp boundary line” distinguishing between propositions like “here is a hand” and “at this distance from the sun there is a planet” (53), and in turn no sharp line between “rule” propositions (those of which we are sure) and empirical propositions (those which are justified by our rules) (319). He suggests that basic propositions vary and can be doubted, but only in context of fixed others. In line with the river-bed analogy, he likens this to sediments that are picked up from one part of the bed, carried off, re-deposited elsewhere, etc.