Introduction:

In his famous article, "A Defence of Common Sense," G.E. Moore appeals to common sense in order to attack against various philosophical positions that dney the reality of Time, material things, space, and selves. In this brief "shorty," I try desperately to respond to all of the questions posed to us. Let's get started.

Is it Possible? Sure...But it Ain't Actual:

Moore argues that it could have been the case that Time, material things, space, and selves all might not have been real. However, he rejects the view that they are in fact not real for the simple reason that the propositions he lists in (1) are, in fact, true (180). One might ask why he uses the propositions in (1), as opposed to those in (2), in formulating this argument. One possible response to this question is to say that the propositions in (1) concern Moore’s own personal knowledge of the reality of Time, material things, space, and selves, while the propositions in (2) concern the fact that Moore is certain of other people’s knowledge of the truth of these same propositions as well. Thus, given that Moore’s argument rests upon his own certainty about the reality of Time, material things, space, and selves, he need not appeal to other people’s knowledge of such reality, but rather he only has to appeal to his own knowledge.

Is the argument a good one? I’m torn on this issue. On the one hand, Moore appears to be dogmatically asserting the truth. And blindly asserting the truth of something, shouting it at the top of one’s lungs, or even slapping someone in order to try and prove the existence of the material world (or anything for that matter) does not seem like a fruitful method of argumentation. We attack this style of argumentation when anyone else is wielding it (such as the certainty of religious conviction), so why shouldn’t we hold Moore to the same standards? On the other hand, I think we all have Moorean sympathies: if someone denies the existence of physical objects, say my hand, I have the desire to reach out and slap him with it and ask him to repeat his skeptical claim. In the end, I feel that this argument is only effective when it is joined with Moore’s arguments concerning the impossibility of holding skeptical views (which we will discuss in a little bit).

Why have all the philosophers missed it? I don’t believe they have. Moore himself admits that many philosophers have maintained that we know the propositions of (1) to be highly probable, but that we are just not able to attain infallible knowledge of such things. What philosophers have missed, I suppose, is Moore’s further argument: that by uttering ‘we’ in the last sentence, we are already presupposing the very material things and other selves that we are, at the same time, skeptically rejecting (181). But I am sure that many of these philosophers would merely retract their statements, pass their failure off as a difficulty with expressing such negative claims in ordinary language, and retreat to their nihilism.

The Self-Denying Philosopher

Moore’s argues that if any philosopher has denied the proposition (that some propositions belonging to each of the classes of (2) are true), then it follows from the fact that he denied it that he must have been wrong in denying it (179). His argument here is pretty slick. If by ‘philosopher’ we mean what we commonly mean by the term, then a ‘philosopher’ is a human being—a human being with both a body and experiences. Thus, if a ‘philosopher’ has denied the proposition, then it is the case that a human being has denied the existence of human beings.

I’m not sure if Moore’s argument is completely successful. He wraps up his conversation here by saying that any view incompatible with the truth of the propositions in (1) can only itself be true if no philosopher has ever held the view—precisely because our definition of ‘philosopher’ contradicts such a view (179). But this seems to rest upon understanding ‘philosopher’ as we all commonly do. If you questioned someone who really held this view, I’m not sure if they would grant you such a translation of ‘philosopher’. By granting Moore the translation, it seems that the rest of his argument follows. So why not just doubt the translation? 3

Moore’s first argument (that we analyzed aboce) appears to be that we have a lot more evidence for believing in a variety of things (time, material objects, etc.) than we do for believing skeptical claims. This second argument is different. For he is not just making a pragmatic claim about our beliefs, he is saying that anyone who has attempted to hold a skeptical view concerning these things has been holding an inconsistent view. Thus, it is impossible to hold such a view, since we value consistency.

Radical Rick & Modest Mack: Two Dialogues

Moore outlines two positions (one radical and one modest) that he believes philosophers have mistakenly held throughout our history. Let us define our two views. First, there is the “radical” view. The radical view states that it is consistent to hold that none of the classes of propositions in (1) or (2) are true—that is, it is not inconsistent to deny the truth of any of the propositions in either (1) or (2). Moore argues that this position cannot be consistently maintained, as the following dialogue is supposed to show:

Moore - “Tell me, Radical Rick, do you deny the propositions of (2)? Do you deny that there are other selves who have had corresponding knowledge of the propositions of (1)?

Radical Rick - “I do indeed, G.E., I do indeed.”

Moore - “And, my dear friend, are you a philosopher or aren’t you?

Radical Rick - “Your question games again, eh? Alright, I’ll play along. Yes, I’m a philosopher. And proud of it, I might add.”

Moore - “Excellent. And tell me, what exactly is a philosopher?”

Radical Rick - “Well, I guess a philosopher is someone who thinks about and engages with the questions typically associated with the field of philosophy; moreover, he or she is someone who has had training in this field and often holds a job at a university.’

Moore - ‘My dear friend, Rick, you make this too easy. Is it necessary to be a person in order to be a philosopher?”

Radical Rick - “Don’t be silly! Of course it is!”

Moore - “But don’t you see! By ‘philosopher,’ you and I both mean a human being—someone with a human body. And you vehemently attack other philosophers for arguing that other selves exist. But in doing so, in attacking the views of other philosophers, you are quietly admitting to everyone that you also believe in the existence of other selves—you’re arguing against them!”

Moore argues that such radical positions undermine themselves and that philosophers have merely been mistaken in holding such views. It is inconsistent, Moore maintains, for a philosopher to deny the existence of other selves, and then proceed to talk about the views and opinions of other philosophers and to argue against them (given that these philosophers are, by definition, other selves).

The “modest” view, on the other hand, states that while we can assert propositions of class (2), none of us knows for certain any propositions that assert the existence of material things and other selves. Moore argues that this “modest” position cannot be consistently maintained because the view entails self-contradictory, mutually incompatible propositions. To see why, let’s consider another dialogue:

Moore - “Are you saying that you don’t believe in the existence of material things or other selves?

Modest Mack - “Of course, I believe in material things. We all do! The point is, there is no way for us to be certain that these things are true!

Moore - “Oh really! Is that right?

Modest Mack - “That’s right.”

Moore - “Then what is this ‘we’ and ‘us’ that you speak of?”

Modest Mack - “What?”

Moore - “I’ve got you now, Modest Mack. By saying that ‘we’ believe these propositions and that there is no way for ‘us’ to be certain of our knowledge, you are making a claim not only about your own lack of certainty, but about a lack of certainty in general among the whole human race! Thus, while you deny the existence of other selves with your first breath, your last breath betrays your commitment to them!”

Modest Mack - “That’s preposterous! Most of us believe in the existence of other human beings. I’m just saying that we can’t be certain of such knowledge.”

Moore - “Ah, Modest Mack, but your very language does not convey this uncertainty. Rather, you are quite certain that ‘we’ do not have infallible knowledge of such propositions. Your certainty, in turn, undermines your skeptical claims.”

Modest Mack - You’ll rue the day you crossed Modest Mack!”

I hope Moore’s point is clear from this exchange. By referring to the uncertainty of human knowledge, philosophers who hold this modest position are implicitly making a claim about all human knowledge, a claim that presupposes the existence of other human beings. Hence, the modest position cannot be consistently maintained.

The Trouble with Sense-Data:

I am really quite confused about Moore’s characterization of “sense data.” Of course, since I don’t believe in sense data, I am tempted to throw a Moorean argument back in his face: I know there aren’t any sense-date—of this I am certain. Your argument establishes nothing. But then he goes on to describe his notion of sense-data—a representation (such as a portion of my hand) which represents the object which I am seeing (my hand). In doing so, I am not sure whether he is locating sense data “out there” in the world or, rather, as a feature of our mental worlds. I do not believe that his argument has established the certain existence of sense-data. But, then again, his definition of sense-data can be read in so many ways, I am not quite sure I am right about this.

-- DanielS - 17 Oct 2005