Clearly he was unastonished by a world of Being. Did anything astonish the man? Was there any philosophical problem he found awesome and bewildering? What about, for example, the problem of how consciousness arises from brute matter?
“I’m amazed by the variety of consciousness and the kinds of things that the human mind can come up with,” he said. “It’s all very splendiferous! But I don’t find the existence of consciousness puzzling.”
I noted how different his attitude was from that of the philosopher Thomas Nagel, one of my intellectual heroes. In his book The View from Nowhere, Nagel pondered at length the mystery of how the mind’s irreducibly subjective character could fit into the objective physical world.
“I’ve never read that book,” Grünbaum said.
But it’s such an important book! I stammered. The Oxford philosopher Derek Parfit declared Nagel’s book the greatest philosophical work of the postwar era.
“Did he?” Grünbaum replied. “Well good for him! But as for me, why should I be puzzled that I’m put together the way I am? I know that many things have shaped my personal history. And there are many things about myself that I don’t understand—why I have certain habits and tendencies, for example. But these are biological or bio-psychological questions. With enough evolutionary theory and genetics and what-have-you, they become potentially interesting. But I don’t sit around wondering why I’m the way I am. I don’t live in a limbo of dubiety.”
If, as Aristotle remarked, philosophy begins with wonder, then it ends with Grünbaum.
Still, the scope of the man’s knowledge was breathtaking. The nature of time, the ontological status of scientific laws, the extravagances of quantum cosmology: all yielded before his precise and rigorous understanding. And the sheer pleasure it all gave him (“I’m having a ball!”) was contagious.
I asked him whether it was possible that an entity in our universe’s distant future—an “omega point,” as some thinkers have called it—might have reached back in time and retroactively caused the very Big Bang that brought the whole show into being.
“Ah,” he said, “you’re talking about retrocausation. Is such a thing possible?” He then launched into a learned disquisition on cause and effect whose virtuosity reminded me of a great diva delivering an opera aria. I listened with more awe than understanding as he wrapped it up: “Well, they got it wrong because they misextrapolated from second-order equations in Newtonian mechanics, where forces are causes of accelerations, to a third-order differential equation, Dirac’s equation, in which forces are not causes of accelerations. So even though when you integrate over all future time you have force quantities in the integral—called ‘pre-accelerations’—that doesn’t mean that this instantiates retrocausation of acceleration by forces. Say, would you like a little gin? I think I’ve got some here.”
As he reached into a lower desk drawer for the salutary bottle and a couple of glasses, I gratefully accepted the offer.
HAD GRÜNBAUM SHAKEN my conviction that the mystery I was pursuing was a genuine one?
Well, the Great Rejectionist had certainly changed my mind about one thing. Contrary to what I had assumed—along with just about every scientist and philosopher who has ever pondered the matter—the Big Bang does not, in itself, make the mystery of existence more acute. It does not mean that the cosmos somehow “leapt into being” out of a preexisting state of nothingness.
To see why, let’s play the tape of the universe’s history backward. With the expansion reversed, we see the contents of the universe coming together, growing more and more compressed. Ultimately, at the very beginning of cosmic history—which, for convenience, we’ll label t = 0—everything is in a state of infinite compression, shrunk to a point: the “singularity.” Now, Einstein’s general theory of relativity tells us that shape of spacetime itself is determined by the way energy and matter are distributed. And when energy and matter are infinitely compressed, so too is spacetime. It simply disappears.
It is tempting to imagine the Big Bang to be like the beginning of a concert. You’re seated for a while fiddling with your program, and then suddenly at t = 0 the music starts. But the analogy is mistaken. Unlike the beginning of a concert, the singularity at the beginning of the universe is not an event in time. Rather, it is a temporal boundary or edge. There are no moments of time “before” t = 0. So there was never a time when Nothingness prevailed. And there was no “coming into being”—at least not a temporal one. As Grünbaum is fond