Lord Martin Rees, Astronomer Royal and president of the Royal Society in Britain, caused something of a flap recently by suggesting that humans may never be able to understand the universe. "Some aspects of reality may elude us simply because they're beyond human brains, just as surely as Einstein's ideas would baffle a chimpanzee," he said.
Einstein used existing mathematics to develop general relativity, describing how gravity controls the universe on the largest scale. Dirac also used "off-the-shelf" mathematics when devising quantum theory, which describes nature on the subatomic level. After decades of trying, physicists have not been able to unify the two theories, maybe because the mathematical tools to do so are beyond our comprehension, said Rees. So too, understanding our own consciousness and self-awareness may require grasping aspects or dimensions of the universe where the human brain is not equipped to go.
Of course, Rees may be right. The universe may exist on scales and in dimensions that will forever elude us. Our brains are finite; the universe may be infinite.
But I wouldn't be too quick to shut the door of progress. History suggests that every generation has had its "dream of a final theory," only to have the next generation take us to a new level of understanding. Yes, our brains are finite, but the future will almost certainly see artificial brains -- not necessarily silicon based -- vastly superior to our own, .
So yes, complete understanding of the universe, or even a complete inventory of what exists, may be ultimately beyond us, which is why it is so silly to base arguments for or against the existence of God on the scientific theory de jour. But I would also suppose that a hundred years or two hundred years from now, our descendants will look back on the science of today with as much condescension as we look back at the science of the medieval university -- or the cosmological thought of chimpanzees.