There are, it seems, three big questions still unanswered by science. One: why is there something rather than nothing (the case for God as creator); the second: how did life evolve from dead matter; and third, what is consciousness (and what is it for). It’s the third that Michael Pollan explores in A World Appears — to say he’s cracked it would be wrong. He has, however, got his readers thinking about it, possibly for the first time. Trouble is, as he observes, we have to use our consciousness to explore consciousness… this isn’t a subject we can investigate from outside.