The Edge of the Universe

 We really need to get the philosophers and the theoretical physicists back in the same room again—or, better still, merged back into the same person, the way they would have been in the eighteenth century. Because the modern physicists keep telling us that they've come up with some theoretical model of the universe that defies the categories of our minds. When we point this out to them, they tell us, "Yeah, it's hard to explain; we can't really picture it; but the math tells us it must be so." 

To this, the philosophers retort: math can't tell us something that violates the categories of cognition and perception! This is because math is itself a product of those same categories. The mind that thinks the math is the mind that struggles in vain to comprehend that which it appears to disclose. Something has gone wrong somewhere!

It is essential to settle at the outset of this critique a common misunderstanding. The philosopher's point is not that nothing could be true which defies the human mind's ability to conceive. The point, rather, (at least if the philosopher is a logical positivist; or a certain kind of Kantian) is that we could—by definition—have no knowledge of such a thing, even if it were real, since all our knowledge comes to us through the limitations of our own conceptual apparatus. 

This, and not any doctrinaire scientific naturalism, is the true basis of the logical positivist's objection to theology. It's not that we can say no infinite good or perfect intelligence could possibly exist; it's that we wouldn't know anything about it, if it did, or be able to formulate any positive claims about it, since our minds are finite. "Nor is it possible to Thought/ A greater than itself to know," as a youthful heretic says in one of Blake's poems. That's really the sum of it. 

But now here come the theoretical physicists—themselves generally a product of a post-theological worldview—and they are bringing metaphysics back in by the rear door. 

They are asking us to believe in things that are literally inconceivable to the human brain. When we ask them how we can do so, they tell us to take it on faith, because the math discloses it. When we ask how we can take on faith an assertion that we are not even able to formulate to ourselves... well, no answer comes to this question because, as mentioned, the scientists and the philosophers are not even in the same room anymore to begin with. 

Let me give you an example. The physicists tell us that the universe is expanding, but finite. We ask what it means for the universe to be expanding. They tell us to picture space and time as a kind of mattress, which is slowly being spread out on the floor. This seems at first to help—but the appearance is deceiving. For we have rendered the concept intelligible only by conjuring a misleading analogy. The analogy is conceivable—but not the claim it is supposed to illustrate. 

For space and time are not actually like a mattress that can be stretched out on the floor. Space and time are the categories of the mind in which alone any possible mattress or floor could be conceived. They cannot be the mattress—for if they were the mattress, what then is the floor? What is the air surrounding and demarcating the limits of the mattress? 

Imagine, if you will, that we were to fly a spacecraft to the outermost edge of this supposedly finite yet expanding mattress. What would we find there, at its outermost boundary, marking the end of space-time? Would it be a kind of wall? But how can there be a wall with nothing on the other side of it? If there is nothing on the other side of it, then what is marking the limit of the space the wall encloses? How can we tell that it has actually ended?  

I had always wondered about this, when speculating on the current models of the universe, only to find my thought reflected back to me succinctly in Xavier de Maistre's Nocturnal Expedition Around My Room—the witty sequel to his even more delightful Voyage autour de ma chambre. De Maistre, in contemplating the night sky, asks: "it would, I believe, be ridiculous to think that there is [at the edge of it] some barrier after which there is mere nothingness, as if nothingness were easier to comprehend than existence!" (Brown translation throughout.)

But then, this is already gesturing to the old problem that eventually forced me to abandon logical positivism as unsatisfactory in turn. For, as absurd as it seems to be to ask us to accept that space has a limit, it seems inconceivable too to posit that it has none. Both infinity and non-existence exceed the bounds of finite human intellect, and, even if one seems slightly easier to comprehend than another, as de Maistre indicates, neither is truly comprehensible. 

And so, in this domain as in so many others, we seem to be confronted with inconceivabilities any way we turn. Either space is infinite, or it is finite; and neither thought will fit within the confines of our minds. Either each of us enjoys personal immortality, or else we will cease to exist some day—neither of which is conceivable, because to exist in eternity would mean never to change, which in turn would mean a cessation of time and would amount to the same thing as non-existence, which is likewise impossible for the human consciousness to imagine of itself. 

(For what it's worth, de Maistre is concerned with this philosophical riddle too, amidst his various Shandean digressions. "I will die one day? I will die? I—the person speaking, the person able to feel and touch myself—I might die? I find it rather difficult to believe.")

I can't forgive the physicists for trying to make us believe that space has an end. Space is merely a category of the mind, and our minds generate it in the course of their perambulations through the unknowable Kantian noumena, and would continue to generate it beyond the outer reaches of any cosmic map, in the same way that if you drive a vehicle off the edge of a world in certain video games, the program will just keep generating blank space no matter how far you go, until the end of time. 

But I also couldn't forgive the scientists if they tried to tell us the opposite: that space and time are infinite. That seems just as impossible for the finite human mind to conceive!

So perhaps there is nothing to be gained from putting the philosophers and the scientists in the same room or body again after all; perhaps some of the fundamentals of life, the deepest structures of perception and reality, will remain always a hopeless riddle.