I conclude then that logic is a real insight into the way in which real things have to exist. In other words, the laws of thought are also the laws of things: of things in the remotest space and the remotest time.
This admission seems to me completely unavoidable and it has very momentous consequences.
In the first place it rules out any materialistic account of thinking. We are compelled to admit between the thoughts of a terrestrial astronomer and the behaviour of matter several light-years away that particular relation which we call truth. But this relation has no meaning at all if we try to make it exist between the matter of the star and the astronomer's brain, considered as a lump of matter. The brain may be in all sorts of relations to the star no doubt: it is in a spatial relation, and a time relation, and a quantitative relation. But to talk of one bit of matter as being true about another bit of matter seems to me to be nonsense. It might conceivably turn out to be the case that every atom in the universe thought, and thought truly, about every other. But that relation between any two atoms would be something quite distinct from the physical relations between them. In saying that thinking is not matter I am not suggesting that there is anything mysterious about it. In one sense, thinking is the simplest thing in the world. We do it all day long. We know what it is like far better than we know what matter is like. Thought is what we start from: the simple, intimate, immediate datum. Matter is the inferred thing, the mystery.
In the second place, to understand that logic must be valid is to see at once that this thing we all know, this thought, this mind, cannot in fact be really alien to the nature of the universe. Or, putting it the other way round, the nature of the universe cannot be really alien to Reason. We find that matter always obeys the same laws which our logic obeys. When logic says a thing must be so, Nature always agrees. No one can suppose that this can be due to a happy coincidence. A great many people think that it is due to the fact that Nature produced the mind. But on the assumption that Nature is herself mindless this provides no explanation. To be the result of a series of mindless events is one thing: to be a kind of plan or true account of the laws according to which those mindless events happened is quite another. Thus the Gulf Stream produces all sorts of results: for instance, the temperature of the Irish Sea. What it does not produce is maps of the Gulf Stream. But if logic, as we find it operative in our own minds, is really a result of mindless nature, then it is a result as improbable as that. The laws whereby logic obliges us to think turn out to be the laws according to which every event in space and time must happen. The man who thinks this an ordinary or probable result does not really understand. It is as if cabbages, in addition to resulting from the laws of botany also gave lectures in that subject: or as if, when I knocked out my pipe, the ashes arranged themselves into letters which read: 'We are the ashes of a knocked-out pipe.' But if the validity of knowledge cannot be explained in that way, and if perpetual happy coincidence throughout the whole of recorded time is out of the question, then surely we must seek the real explanation elsewhere.
C. S. Lewis