Here is a necessary truthg: If something is red, it cannot at the same time not be red; it is impossible for it to be simultaneously red and not-red. If I see a green leaf, and know that green is not red, I can conclude, with all the assurance of which mortals are capable, that the leaf is not also red. (It may turn red; another story.) I cannot, however, conclude that it is impossible that the leaf be red.

Easy enough, you say. Good; we're warming up. Here's one a bit harder: our glasses couldn't stay on if our noses were shaped differently; but glasses do stay put, therefore ouyr noses must have their present shapes. Still with me? OK, one last one: human life would be impossible if physical laws were very different, but here we are, so the universe must be the way it is. Ain't that a relief?

Thus the anthropic cosmological principle, due to Barrow and Tipler. In the strong form I just gave it, and which they favor, it is an elementary fallacy in modal logic, formally akin to ``Have you stopped beating your wife yet?''; also a relapse into Aristotelianism of the worst sort. It gets its plausbility by being confused with the following, weaker and valid mode of argument: ``X only if Y; but X; thus Y, too.'' For instance: ``Bullets are found in people's spines only if they were shot at with a loaded gun; Mr. Thipps has a bullet in his spine; therefore somebody shot at Mr. Thipps with a loaded gun.''

Tipler is not satisfied with the reasoning of mystery stories (or even with doing physics, alas; he was good). He has gone on from believing in our necessary presence in the universe to the necessity of intelligent life persisting forever. As every schoolchild knows, the universe is expanding in the aftermath of the Big Bang; but it's decelerating, because gravity pulls bits of matter together, slowing the expansion. A key question in cosmology is whtether the expansion will continue forever, or whether gravity will eventually slow it to a halt and then reverse it, bringing everything together in a Big Crunch. Tipler supposes that the universe is so dense that the latter will happen, that the universe is ``closed.'' Since, as a consequence of quantum mechanics, the global state of the universe never really looses any information (it just gets, so to speak, misplaced), shortly before the Big Crunch all the information about everything which ever happened would be in one place. Tipler further believes that there will be computational entity waiting to extract from this all the information about every person, every sapient creature, who has ever lived, and then bring them to simulated lives of bliss, the simulation enduring, in subjective time, forever. It will do this because it will know, from game theory, that it pays to be nice.

Even if we went crazy and granted all the rest of Tipler's points, the last doesn't follow. The game-theoretic arguments for benevolence hinge crucially on the other guy being able to do something to you, e.g. hit back. But, by hypothesis, Omega has nothing to gain or lose from anyone else. In the words of the button: ``Yea, though I walk through the valley of the shadow of death, I will fear no evil, 'cause I'm the meanst, baddest sonofabitch in the whole damn valley.'' Omega might be so kind as to resurrect us all in Heaven (Tipler is a believer in universal salvation), but it might bring some of us back to a Hell, or separate copies to several afterlives at once, and find some sapients too boring to be worth any hereafter at all. Clearly, one wants to get on its (or, rather, Its) good side one way or another.

A fine way to do that would be to build Omega, and to do that it would be nice to make sure you have no interfering rivals. (There can be Only One.) Here at last is a sensible motivation for galactic, indeed universal, conquest: not mere transient temporal dominion, but the veritable kingdom, and the power, and the glory, forever and ever. And if the powers that will be are the ordainers of God, or a reasonable facsimile thereof, why then the struggle for power may get very nasty indeed. What, after all, are a few intelligent species when eternity is at stake?