Bill Vallicella quoted this parting-shot that Lawrence Krauss fired at William Lane Craig:
Classical human reason, defined in terms of common sense notions following from our own myopic experience of reality is not sufficient to discern the workings of the Universe. If time begins at the big bang, then we will have to re-explore what we mean by causality, just as the fact that electrons can be in two places at the same time doing two different things at the same time as long as we are not measuring them is completely nonsensical, but true, and has required rethinking what we mean by particles. Similar arguments by the way imply that we often need to rethink what we actually mean by ‘nothing’, from empty space, to the absence of space itself.
Vallicella focuses on the claim about “nothing”, and has a rollicking good time with it. I was more interested in the first few sentences, since I think Krauss is onto something but that he misses the real culprit. It’s not that our “common sense notions” are wrong, nor is there a problem with what other philosophers and scientists in this context call our “intuitions” (whatever they are), it’s rather that we’ve recognized that the common sensibles do not have an absolute objectivity. We’ve long grown accustomed to accepting that the proper sensibles (like flavor, scent, color, etc.) have only an imperfect objectivity, but we always figured that the common sensibles were not subject dependent but were really in things as primary qualities. Berkeley denied this long ago, and now experience is starting to force us to take his position more seriously, even if we don’t take it up entirely.
The basic position reduces to a dispute between Plato and Aristotle about what the study of nature is given that it is about both a.) a reality, and b.) what is given to sense. Aristotle’s empiricism won the debate from the Medieval times to the 20th century, with its claim that sensation exhausts the content of nature in a more or less perfectly objective way, and that therefore natural science was a perfectly objective science. From the time of the Empiricists and Newton this position was modified to saying that only the common sensibles (like magnitude, time, number, position, place, etc.) were perfectly objective and universal, whereas the proper ones were not. There might not be color or taste, but there was obviously (so we thought) a three dimensional extension with a single time, where parts are either here or there. But now – As Plato and Berkeley have been arguing all along – the scientists are forced to accept that those sensibles are no more ultimately and absolutely objective than scent or flavor. This changes nothing about what natural science does, but it does lead to a very different account of its foundations and the sort of objectivity that it can boast of.
