God, they will insist, is a spirit and is to be worshipped in spirit. Therefore an experience which is chemically conditioned cannot be an experience of the divine. But, in one way or another, all our experiences are chemically conditioned, and if we imagine that some of them are purely ‘spiritual’, purely ‘intellectual’, purely ‘aesthetic’, it is merely because we have never troubled to investigate the internal chemical environment at the moment of their occurrence.