G.E Moore- Need A Hand?
G.E Moore (1873-1958 A.D.)
All An Illusion?
Have you ever heard of a skeptical scenario? If you’ve seen the Wachowski sisters’ film The Matrix, you have—whether you realize it or not. Even if you haven’t (though it’s definitely worth a watch), you may have at some point pinched yourself to check if you were dreaming. Both The Matrix and the nature of dreams have made many of us question if what we’re seeing, smelling, hearing, tasting, and touching is truly real. This is the essence of the skeptical scenario: we could be in a situation where our experiences are mere illusions, yet they’re indistinguishable from reality. In other words, there’s no way to be certain we’re not dreaming, trapped in a matrix, or just a brain floating in a vat of fluid, stimulated by electrodes.
The most famous—and possibly the first—formulation of the skeptical scenario comes from French philosopher René Descartes (1596–1650 A.D). In his work Meditations on First Philosophy, Descartes imagines being deceived by an evil demon, capable of creating illusions that feel exactly like real life. He begins to doubt his sensory experiences, as well as the foundations of mathematics and logic. With sensory, mathematical, and logical truth now in question, what could he be certain about? There was one thing Descartes found he could be sure of: his own existence. To doubt is to exist. Even if a demon were deceiving him, there must be something there for the demon to deceive in the first place.
Closing Pandora’s Box
The fact that we can’t rule out the skeptical scenario has troubled philosophers ever since Descartes introduced it. Not only does it make us question the nature of material reality, but it also challenges what we know about the world around us. We could, theoretically, doubt almost any belief about the world, but a particularly famous question among philosophers is, “Do I know I have hands?” This may sound odd, but consider the following argument:
If I don’t know that I’m not dreaming, then I don’t know that I have hands.
I don’t know that I’m not dreaming.
Therefore, I don’t know that I have hands.
Many philosophers have attempted to refute this argument, and one of the most famous responses comes from G.E. Moore (1873–1958 A.D) in his work Proof of an External World.
Here Is One Hand…
Moore’s argument is simple: he knows he has hands. During his lecture (the source of this example), he can actually see his hands waving in front of him. As he puts it, “I can prove now, for instance, that two human hands exist. How? By holding up my two hands and saying, as I make a certain gesture with the right hand, ‘Here is one hand,’ and adding, as I make a certain gesture with the left, ‘And here is another.’” Moore’s argument can be summarized like this:
If I don’t know that I’m not dreaming, then I don’t know that I have hands.
I know that I have hands.
Therefore, I know that I’m not dreaming.
This reasoning follows a logical principle called modus tollens, which works as follows:
If p, then q.
Not q.
Therefore, not p.
Here’s a similar example with sentences instead of symbols:
If Sherlock Holmes knows the butler murdered Mr. X, then he knows the culprit.
Sherlock Holmes does not know the culprit.
Therefore, Sherlock Holmes does not know that the butler murdered Mr. X. Elementary.
But where does Moore get his proof that he knows he has hands? He doesn’t derive it from anywhere; he simply insists he knows it. Moore’s other works further explain why he believes he can make this direct assertion.
Moore’s Magic Touch
In A Defence of Common Sense, Moore argues that skepticism is self-contradictory. He begins his essay with two bold, controversial claims:
I am a thinking human who has had experiences, has a relationship with objects around me, and knows these things with certainty.
I know there are other people like that.
Now, consider what it would mean to truly believe the skeptical argument. You would have to accept that you can know nothing about anything, except that you are a thinking being. Yet, in daily life, you speak with “other people,” act as if you know things, and live as though you’re certain that skepticism is false. Moore expresses it this way:
“The fact is, of course, that all philosophers have belonged to the class of human beings which exists only if (2) be true: that is to say, to the class of human beings who have frequently known propositions corresponding to the propositions in (1). In holding views incompatible with the proposition that propositions of all these classes are true, they have, therefore, been holding views inconsistent with propositions which they knew to be true; and it was, therefore, only to be expected that they should sometimes betray their knowledge of such propositions.”
When Moore asserts that he knows he has hands, he’s making a common-sense claim about the world. To him, philosophy should start from these common-sense claims. The burden of proof, he argues, is on the skeptic to show why we should accept their machinery of doubt.
Perhaps Moore’s argument doesn’t convince you, and you still find the skeptical argument compelling. Or maybe Moore has managed to sway you. Either way, Moore’s view is often unpopular with people I’ve discussed this with, each having their own reasons. But, personally, his argument still holds a special place in my heart.