Philosophy begins with science.
How do we know this? We can try to begin with philosophy. We can start with Cartesian doubt. Unfortunately for the history of philosophy, Rene Descartes did not take his first philosophy far enough. He began his night of doubt by questioning the reliability of his senses and came to the recognition that a demon—perhaps beneficent, perhaps malicious—could be the source of all his sensations and thoughts. But all was not lost. Asking “do I even exist?” he noticed, entailed something existing to ask the question. Furthermore, that he experienced this something-asking-the-question as himself was enough to demonstrate that some sort of himself existed, even if produced by a demon. In short, thinking about his existence proved in some fundamental way—Descartes realized—that he must exist. In this sense his existence could not be denied, even by God.
That was easy enough. But there are other things to doubt. Descartes recognized the difficulty of determining whether dreams were more real than waking life—a problem famously presented in the inner chapters of the Chuang-Tzu. But here Descartes failed to recognize that there is an identity problem. The problem is this: my thoughts often go away—when I sleep and do not dream, when I am knocked out, when I am subjected to general anesthesia (although we can excuse Descartes for not being aware of this last). When my thoughts resume, how do I know I am the same “I”? Certainly I feel that I’m a continuing entity, but that could be a simple trick of Descartes’ demon.
And there is an even deeper identity problem. My thoughts are never the same. They are diverse, not just in subject but in content and feel. What connects all these thoughts into a single “me”? We must remember that for Descartes, the word “thought” encompasses not just our internal dialog of words, but all of our feelings and sensations. What unites a pain in the knee with a feeling of elation? What unites a smell of roses with an experience of blueness? What unites any of these with my thought “Cogito ergo sum”?
And there is a continuity problem. One moment I may be thinking about what I am and if I even exist, and the next moment I may be wondering where I should eat lunch. A moment later I feel a muscle twitch in my arm. Perhaps my arm, hunger and lunch are all illusions, but nonetheless I experienced these in succession without any way of explaining (if experiences are all I am) how or why one led to the next. That is the continuity problem, and it only increases the difficulty of identifying all these experiences as the same me. (Of course, I have a sense of them as “me” but that could be a trick by the demon.)
Furthermore, what separates my thoughts from yours? What makes mine belong to me and yours belong to you? It does not seem to be something that our thoughts and feelings themselves control. They just are, and in being seem to belong to me or to you. But why?
At first philosophy, all I know about myself is that I am a bundle of experiences. Or I seem to be. But what “bundles” these experiences together? What makes them mine? What am I—what can I possibly be—that I experience this bundle as myself? These questions need answers, but at this point it is unclear how we can answer them.
Descartes makes a logical mistake here. “I am, I exist—that is certain; but for how long do I exist?” he asks himself. “For as long as I think,” he answers, “for it might perhaps happen, if I totally ceased thinking, that I would at the same time completely cease to be.” From this he draws the invalid conclusion that “[thought] alone is inseparable from my nature.” Yet, if thinking proves his existence, it doesn’t follow that thought alone is inseparable from his nature. And it certainly does not follow, as he writes shortly afterwards, that the
knowledge of my being does not depend on things whose existence is not yet known to me, and consequently and even more certainly, it does not depend on any of those things that I can picture in my imagination. …
But what then am I? A thinking being. What is a thinking being? It is a being which doubts, which understands, which conceives, which affirms, which denies, which wills, which rejects, which imagines also, and which perceives. (All quotes from Second Meditation, Laurence J. Lafleur translation, 1960.)
In attempting to tease out his nature from cogito ergo sum Descartes has fallen into a trap. True enough, thinking about his existence is logically necessary if he is to have knowledge of his existence. But neither his existence nor the nature of his existence is logically dependent upon his having knowledge of his existence. Contrary to his claim, it is entirely possible that Descartes’ “knowledge of my being” is dependent on something whose existence is at this point unknown to him. Logically, for example, it could be dependent upon the actual existence of his physical body (even though he currently can’t be sure it’s real) since it could be his body which generates his thoughts. He has confused “knowledge of my existence” with “nature of my existence”—”I know I am” with “what I am.”
But accusing Descartes of a logical error raises the specter of another doubt. How can we know if our sense of what is logical and illogical is reliable? Where does “logic” come from? And whence my sense of what is logical? Perhaps the demon instilled me with this sense of logic—how then can I know it’s reliable? How am I to determine whether my claim that Descartes made a logical mistake has any truth value? And the same goes for my sense of “truth.” Is it anything more than a preference I have—a preference instilled in me willy-nilly by God or demon?
It seems that we are stuck. If our sense of logic and truth is not reliable, then our thoughts can never be reliable and we are at a dead end, as far as philosophy goes. We must give up on rational thought. So what next? How can we proceed? Or can we?
Of course we don’t know that logic and truth are unreliable. We don’t know if they have a universal basis, or if they’re just something locally instilled in us by the demon. And we don’t know the demon’s game—are its intentions beneficent or malicious?
Rationalism dies here. Analytic philosophy dead-ends. At this point we can only proceed with working assumptions. We are forced to be pragmatic and see where that gets us. And our first working assumption must be that logic is reliable enough, that the tools we have to determine truth are valid enough—at any rate our thoughts are useless (outside of social contexts) without these assumptions. And being pragmatic, we will try to maximize the usefulness of our thoughts. Let’s see where this approach gets us.
It doesn’t lead us to certain knowledge about our nature or the nature of the world—we’ve already seen that. Analytically, we can’t get to final answers. But we seem to have other tools—we can use our senses to study the world empirically, we can develop synthetic knowledge of ourselves and the world using the scientific method (which seems to be a method of maximizing the usefulness of our thoughts). How does this help? Well, we can lay down some possible world views—supernatural, natural, and so on—and see which one seems to fit best with what we discover. Our answers will never be final, since they will rely on empirical knowledge—but maybe this fact itself is an essential component of understanding ourselves.
Back to Identity
But let’s not get too far ahead. We still have an identity problem. Before continuing, it may be fitting to summarize where our Cartesian doubt has left us. Our senses are sometimes not reliable, but it may be that neither are our thoughts, even our sense of logic and truth may be something local instilled in us by a demon. We can know that we exist (at least when we ask the question), and we can presume that we exist whenever we have experiences, but we can’t say what we (as these experiences) are or where we (as these experiences) come from, or what (outside of the demon) provides identity to these experiences we think of as us, or what separates your experiences, dear reader, from mine.
We have not yet—but we must—push these questions to the demon. We will want to do this because if we are reliant on the demon for our existence and identity, then we have to seek the answers to our questions there. When we do so, we discover that if the demon also has thoughts and experiences—if it is through thinking and experiencing that the demon instills us with the same—then it also has an identity problem. Where do its thoughts come from, and what makes those thoughts belong to it? What gives the demon its continuity and identity? We could postulate a regression of demons, but that seems never-ending.
Maybe we are thinking about this wrongly.
The problem with thoughts, we saw earlier, is that they are never the same. Because of this simple fact, there is a problem of continuity and identity. And we must remember that when we talk of “thoughts” we are talking about consciousness—about everything we seem to experience. The smell of cinnamon, the redness of a cardinal flying past the window, the taste of garlic, the dull throbbing of a headache, the excitement of winning a poker hand, thoughts about existence, even thoughts about gods and demons—these experiences are so diverse, so unlike each other that we are hard pressed to identify anything they have in common. (Note that we are not talking about what these experiences reference, but about their internal content. It doesn’t matter to the point at hand whether their references are valid or invalid, exist or do not exist.)
Now, one thing that seems to unite them is that they are all sensations of one sort or another—they are all experienced, yes. But what provides continuity from one to the next, what unites them into my experiences, my sensations? Perhaps I can point outside myself to the demon. But if I attribute these experiences which make up me to an external demon—how does that demon go about creating the experiences that become me, and separating them from the experiences that become you?
Of course, the demon faces the same dilemma—if it also experiences thoughts and feelings. It seems, logically (and therefore provisionally, given our uncertainties about logic), that the only way to resolve this without an infinite regression of demons, is to assume that the demon does not have thoughts and feelings. Whatever the demon is, it is not like us. It is not experiential. Making this step allows us to have a demon who is our source and accounts for our identity, yet does not have to face its own Cartesian doubt. This move, it seems to me, brings clarity.
In fact, it seems that the only good way to resolve the continuity and identity problems which exist when we consider experience by itself, is to postulate a source for our experiences which—whatever it is—is not experience. If this source is our demon, then it is a demon that does not think or feel. This doesn’t mean we know what the nature of the demon is, but we do know what it is not. And that is a start.
However, one thing we can say about the demon’s nature is this: whatever that nature is, it encompasses the capacity to create our experiences. We must still ask how the demon distinguishes my experiences from yours—the answer, perhaps, is that it doesn’t have to. Perhaps we are products of different demons, since nothing forces us to conclude that there must be a single demon. This thought raises the interesting prospect that Descartes’ demon—and ours—is none other than the body itself. By postulating physical bodies, we have a potential (and common sense) resolution to the continuity and identity issues that have been raised. It would follow that the nature of our bodies must encompass the capacity to create the sensations (including thoughts) which we experience as us.
Previously we saw that when Cartesian doubt is followed to the end, we reach a point where we must abandon rationalism. Even our sense of logic and truth can be questioned, and our only resort is to embrace them with reservations. Like our senses, we cannot be sure of their reliability. Nevertheless, we seem to have no other tools with which to know the world. We have no other manner of addressing our doubts. Answers with rational, logical certainty are beyond us. But we have the usefulness of the scientific method and that is the next best thing. It allows us to move forward from our Cartesian doubt in a pragmatic manner—by postulating alternative world views (naturalism, supernaturalism, etc) and seeing which one best fits the evidence from science and fits the results of our attempt at first philosophy.
I said at the beginning that philosophy begins with science. Perhaps that is not correct. But Descartes’ method has demonstrated, if nothing else, that philosophy must end with science.