Why Does the World Exist: An Existentia - By Jim Holt Page 0,24
the argument not merely valid, but also (as logicians say) sound?
Well, the finiteness and contingency premises seem okay. But the third premise, that of independence, is more dubious. Can we really be sure that the nonexistence of one thing does not entail the existence of something else? Think again of It’s a Wonderful Life. In the alternative world where George Bailey never existed, many other possible things did exist as a consequence—like the sleazy bars and pawnshops of “Pottersville,” which the greedy banker Mr. Potter would have created had decent George not been around to stop him. Contingent things are not so independent after all. Each thing, no matter how shaky its own claim to existence, seems implicated in a web of ontic interdependency with many other things, both actual and possible.
If a cinematic example is too fanciful for you, consider a more austere, scientific one. Suppose the world consisted of just two objects, an electron and a positron in mutual orbit. Relative to this “pair world,” is there a possible “singleton world” in which only the positron exists? One might think so. But the move from the pair world to the singleton world would violate one of the bedrock principles of physics: the law of charge conservation. The net charge of the pair world sums up to zero, since the positron has charge +1 and the electron has charge –1. The net charge of the singleton world is +1. So moving from the pair world to the singleton world is tantamount to the creation of a net charge—a physical impossibility. Although the electron and positron are individually contingent, each is existentially linked to the other by the law of charge conservation.
Then how about moving from the pair world directly to nothingness? Alas, that’s not physically possible either, for eliminating the electron-positron pair would violate another bedrock principle of physics: the law of mass-energy conservation. Some new entity—a photon, say, or another particle-antiparticle pair—would have to appear in their wake, as a matter of physical necessity.
The hitch here seems to be the same one that both Bergson and Rundle encountered, but in a different guise. In all three cases, absolute nothingness is thought of as a limit, one to be approached from the world of being. Bergson tried to approach it by imaginatively annihilating the contents of the world, only to be left with his own consciousness. Rundle tried a similar imaginative route and also fell short of the goal, ending up with an empty spatial container. Both concluded that absolute nothingness was inconceivable. The subtraction argument tries a different tack, seeking to reach nothingness via a series of logical moves. But the reasonable-sounding intuition behind the subtraction argument—if there are some objects, there could have been fewer of them—runs afoul of a set of fundamental physical principles: the laws of conservation. And even if those laws were somehow suspended, it is by no means clear that the world’s ontological census could be steadily reduced by decrements of one, all the way down to zero. Perhaps the absence of one thing, in either imagination or reality, always entails the presence of another. Delete George Bailey from the scheme of things and up pops Pottersville.
The apparent moral is this: it’s no simple matter to get from Something to Nothing. The approach is asymptotic at best, always falling short of the limit, always leaving some remainder of being, however infinitesimal. But is that surprising? To succeed in reaching Nothing from Something, after all, would be to solve the riddle of being in reverse. Any logical bridge from one to the other would presumably permit two-way traffic.
If it seems easier in the imagination to get from Something to Nothing than the reverse, that’s because both the starting point and the terminus are known in advance. Suppose you sit down at a computer terminal in the reading room of the New York Public Library on Forty-second Street. There’s a single character on the screen—say, “$.” You press the delete button, and the screen becomes blank. You have effected a transition from Something to Nothing. Now suppose you happen to sit down at a terminal with a blank screen. How do you go from Nothing to Something? By pressing the undelete button. When you do so, however, you have no idea what will appear on the screen. Depending on what the previous user was up to, it could be a lapidary message or a mere jumble of characters. The transition from Nothing to Something seems