..is what humans are built for. I seriously don't think that we can know everything, or frankly should even bother to try. The beauty of thought, from birds all the way to Einstein, is the way we can approximate answers that aren't absolutely perfect, but that are good 'working models'. It is the way brains are wired, after all, and is probably the reason that AI doesn't work. In other words, I suggest that the search for ultimate truth flies in the face of what we are capable of, at least this early in evolution.