“It is only by making physical experiments that we can discover the intimate nature of matter and its potentialities. And it is only by making psychological and moral experiments that we can discover the intimate nature of mind and its potentialities. In the ordinary circumstances of average sensual life these potentialities of the mind remain latent and unmanifested. If we would realize them, we must fulfil certain conditions and obey certain rules, which experience has shown empirically to be valid.”