experience shows us how fragile, and dependent upon other things, the existence of intelligence is. In our experience minds require brains which are fragile, dependent, late, and unusual arrivals in nature. ‘Generation, that is, animal or vegetable growth from previous animal or vegetable life, is by contrast common, and as far as we ever observe, necessary for the existence of intelligence. So, arguing from experience, it is much less likely that there is a self-sustaining mind than some other physical cause responsible for the whole show.
