This is one of those fun-to-think-about questions. A brain isn't much to look at, after all. It's about the size of your two fists put together, three pounds to hold, but oh my, what it can do.
Brain with exclamation point
Robert Krulwich/NPR
With our brains, we can think backwards, imagine forwards, conjure, create things that don't exist, leap vast distances. For example, suppose I say to you, close your eyes and imagine this:
...let's you and I rocket off the Earth and keep going, out past Neptune, then past the nearest star, then on and on across a patch of cold empty space until we reach an interstellar gas cloud glowing pale blue, and when we get there, let's fly to the top, hover near a small baby star softly glowing, and move in closer to see it peeking out from the top of the cloud...
Can you see this with me? I bet you can. You can fly with me across vast distances, go to impossibly faraway places because you have the tool that lets you — that hunk of flesh in your head.
Brain cloud
Robert Krulwich/NPR
"Our creatures are our thoughts," said the poet John Donne way back in the 1620s, and our thoughts "reach from east to west, from earth to heaven; that do not only bestride all the sea and land, but span the sun and firmament at once; my thoughts reach all, comprehend all."
If a brain can make crazy leaps across the cosmos and bring extra passengers along (like you when you listen to me), then in a metaphorical way, the brain is bigger than what's around it, wrote 19th century poet Emily Dickinson.
The brain is wider than the sky,
For, put them side by side,
The one the other will include
With ease, and you beside.
I like her confidence. The brain reaches where it pleases "with ease," so she figures it's bigger than everything. It can do things the physical universe can't, like go backwards. ("Let me tell you what happened to me yesterday...") And while I agree with Dickinson, the brain is formidable — does it get the crown?
Brain with crown
Robert Krulwich/NPR
Well, let's hear from the Universe; As critic Kathryn Schulz wrote recently, if you think of the cosmos the easy way, as a giant expanse with stars, planets and gas clouds, then yes, a mind can imagine all that ("and you beside"). But what if we make it a little harder, and consider the mysteries of dark energy, the space/time continuum, Higgs fields, teeny bits of energy popping up out of nowhere and then vanishing into the smallest imaginable spaces? What if I tell you that the faster you go, the bigger you get, until at the speed of light, your mass increases enormously?
That's Silly
"Many people think that this is silly," wrote astronomer Carl Sagan, "and every week or two I get a letter from someone who complains to me about it," but no matter how strange it seems, this happens to be true, experimentally, verifiably true. But truths like these aren't easy to take in. Our minds boggle.
"The universe is not only queerer than we suppose," said the biologist J.B.S. Haldane, "but queerer than we can suppose." In Haldane's view, the universe is bigger than the brain. There are things we just can't know, or even conjure with the brains we've got.
There are philosophers and scientists who say we will never understand the universe, we can't fathom the endless details or make good sense of the whole. We can try, but the universe is too big. The writer John Updike once explained the argument this way to reporter Jim Holt:
"It's beyond our intellectual limits as a species. Put yourself into the position of a dog. A dog is responsive, shows intuition, looks at us with eyes behind which there is intelligence of a sort, and yet a dog must not understand most of the things it sees people doing. It must have no idea how they invented, say, the internal combustion engine. So maybe what we need to do is imagine that we're dogs and that there are realms that go beyond our understanding."
Our brains are magnificent compared to other creatures here on Earth, but up against the universe, we are pitiful. That's the argument, anyway. So does the universe get the crown?
Sun behind clouds
Robert Krulwich/NPR
I don't know. Carl Sagan thought that we humans are good at finding patterns in nature, and if we know the rules, we can skip the details and understand the outline, the essence. It's not necessary for us to know everything. The problem is we don't know how many rules the cosmos has. How many rules does it take to explain the mystery of non-life becoming life, the finite becoming infinite, matter becoming mind, nothing becoming something? A few? Millions? We don't know.
Yet the brain has its champions. "Consider the human brain,"says physicist Sir Roger Penrose. "If you look at the entire physical cosmos, our brains are a tiny, tiny part of it. But they're the most perfectly organized part. Compared to the complexity of a brain, a galaxy is just an inert lump." Yes, it's small, but the human brain has a power that nothing we know of in all the galaxies can match.
So which, then? Brain? Universe? Curiosity versus mystery, which is bigger?
Go Universe!
Speaking personally, I'm rooting for the universe. I don't need, don't want, don't like the idea of one day knowing all there is to know. I don't think we can. I think about Job, the bible's just and honest man, being lifted up high into the heavens so he can see all of God's creation and shrinking painfully away from the sight of "Things too wonderful for me."
I'm not saying we shouldn't try. And even if we amplify our brains with powerful computers, my hunch is the universe will still outwit us, will still be "too wonderful" to be decoded, because we are, in the end, so much smaller than it is. And that's not a bad thing. To my mind, it's the search that matters, that sharpens us, gives us something noble to do.
As the physicist Steven Weinberg famously said, "The effort to understand the universe is one of the very few things that lifts human life a little above the level of farce, and gives it some of the grace of tragedy."
We live to wonder, to ask, to appreciate. Without wonder, why are we here?

I blame Kathryn Schulz for getting me thinking about all this. She wrote a brilliant, provocative review of Jim Holt's new book Why Does the World Exist? that is so much fun to read, you should run, not walk, to find it hereAnd then, because the review leaves you no option, you will, zombie-like, find yourself compelled to pick up Jim Holt's book (I'm halfway through and loving every page) which visits with a bunch of very smart scientists, novelists and philosophers and asks them why the universe came to be. They all have answers, but Jim knows — and they know — that nobody really knows. The conversations are sharp and fun and Jim writes well enough that I never felt too stupid to turn the page. That's rare.