The Flaws in Moore’s Argument
Moore’s proof is more robust than Wittgenstein sometimes characterizes it. It is compelling enough that Wittgenstein feels compelled to critique it; and Wittgenstein seems even to appropriate for his philosophy parts of Moore’s thought in the two essays. Moore’s conclusion is that there are things in existence, i.e., two human hands. And as premises, he holds up his two hands, saying, “Here is one hand,” and then, “here is another.”[i] This argument hinges on three things: 1) that the premises are different than the conclusion; 2) that the premises are known by Moore to be the case; and 3) that the conclusion follows from the premises.[ii] Wittgenstein critiques the second condition. Moore is completely certain that he has satisfied the second condition, which he makes obvious by saying,
How absurd it would be to suggest that I did not know it, but only believed it, and that perhaps it was not the case! You might as well suggest that I do not know that I am now standing up and talking—that perhaps after all I’m not, and that it’s not quite certain that I am![iii]
Moore thinks his knowledge here is completely incontestable and self-evident. This sense of certainty is important, and it will figure prominently in Wittgenstein’s notion of knowledge. But here it is important to see why Moore is wrong to say he knows he has two hands. We should not suggest, after all, that Moore does not know he is “standing up and talking,” but we would suggest that it is incorrect for Moore to say, “I am now standing up and talking.”
For Moore, knowledge of a something is constituted by its being the case; by one’s not “only [merely] believing” it to be the case; and by one’s being “quite certain” that it is the case. This notion of knowledge is what one would call justified true belief. Of course, the difficult criterion to satisfy with justified true belief is the criterion of justification. Moore thinks he is justified to know he has two hands because he is “quite certain” that he has two hands. And this seems correct to us. But just because Moore may be justified in knowing that he has two hands does not mean he is justified in saying he has two hands. The epistemological notion of knowing he has two hands has influenced his grammatical use of “I know…”
Wittgenstein begins On Certainty by saying, “If you do know that here is one hand, we’ll grant you all the rest.”[iv] He goes on in that section to say that from any proposition another may follow, but this entailment doesn’t make the proposition from which others are derived any more certain. That is, B may follow from A, but that doesn’t make A more certain. Further, if I say, “I know I have two hands,” it follows that I have two hands; but that Moore has two hands does not follow from his saying “I know I have two hands.”[v] Another person’s assertion that he knows doesn’t secure objectivity. However, there are two important caveats to the preceding remark. On the one hand, “I know…” does not always mean “I cannot be wrong about…” or “I am certain of…”[vi] A fact is not necessarily entailed by the utterance “I know…” Such a use would result in the most absurd solipsism; but philosophers often commit themselves to such a position. After his psychological reduction, Descartes perceives clearly and distinctly that he is a thinking thing; consequently, he knows that he is a thinking thing. His perceiving clearly and distinctly, i.e., knowing, that he is a thinking thing satisfies him that he is a thinking thing. Similarly, when Moore says, “I know I have two hands,” he makes it clear that he cannot be wrong, that he must in fact have two hands. In both cases, a certainty—a certain piece of knowledge—entails a fact. Wittgenstein denies that certainty can entail a fact. Philosophic uses of “I know…” “seem to describe a state of affairs which guarantees what is known, guarantees it as a fact,” but this guarantee ignores the phrase “I thought I knew.”[vii] Obviously—trivially, even—things are contrariwise. That is, we are left with facts; and to these facts knowledge or certainty need not correspond. The desire to talk about knowledge often confuses us about what it is that comprises knowledge.
On the other hand, when someone else says, “I know…” it doesn’t follow that he does know; but this is not to say that he doesn’t know it. Rather, that another person does know “takes some showing.”[viii] Showing that one knows is central to Wittgenstein’s notion of knowledge and objectivity. We often mistake the grammar of a proposition with a guarantee of the proposition’s being the case. A proposition of the form, “I know…” doesn’t automatically denote a state of affairs—it doesn’t secure objectivity or even necessarily give a piece of knowledge. When someone says, “I know…” the utterance is an indication of assurance; but such an assurance only means that he thinks he is not mistaken.[ix] Someone’s knowledge or certainty does not assure a fact. Rather, the fact—the real existence of a state of affairs—is the possibility of assurance. That is, when someone says he knows something, his interlocutor “must be able to imagine how one may know something of the kind.”[x] Reality and experience—life itself—govern this imagining. In this way Wittgenstein’s philosophy seems to echo Kant’s notion of transcendental idealism: a concept without experience is empty. Moreover, given that the fact is the case does not assure that one knows that fact. For someone to sensibly say to another person, “I know…” the other person must be satisfied with this knowledge. This satisfaction is part of Wittgenstein’s notion of knowledge. As we would like to show, Wittgenstein’s notion of knowledge depends heavily on an intersubjective type of agreement, which goes toward justifying another’s belief that his interlocutor (which is to emphasize Wittgenstein’s focus on utterances) actually knows something.
Someone might ask his neighbor on what day the city collects the garbage. If the neighbor says, “I know it gets collected on Wednesday,” he may be satisfied that the neighbor knows this and that it’s true. If the neighbor takes care of his home, seems concerned with its upkeep, and seems trustworthy, then a person would probably be satisfied. If, however, piles of rubbish lie next to the neighbor’s house and if he seems unconcerned with keeping up his home, then a person would probably be unsatisfied. He would think that his neighbor might not know when the garbage is collected. That is, the neighbor has failed to show that he knows when the garbage is collected. We don’t have to try to infer his mental state—whether it is one of knowing, believing, not knowing, etc.—we can see with our own eyes that he does not know. From his saying, “I know it gets collected on Wednesday,” someone wouldn’t necessarily (that is, have to) think that that’s when it does get collected; and in fact, we would think he does not know.
[i] Moore, “Proof,” 146.
[iii] Moore, “Proof,” 146-7.
[iv] On Certainty, §1.
[v] On Certainty, §13.
[vi] On Certainty, §8.
[vii] On Certainty, §12.
[viii] On Certainty, §14.
[ix] On Certainty, §15.
[x] On Certainty, §18.