The leaders of the scientific thought of last century would have been vastly surprised if they could have foreseen the results of the investigations which were to be made into the constitution of matter and the nature of life; but not even these would have amazed them so much as would other investigations that were to be carried out in a yet deeper and more mysterious region of experience. Perhaps it was because science had been so busy about the more external things, that it had seemed to have no time to spare for the thorough consideration of that which is more truly vital to man than the matter which obeys or opposes him, or even than the physical life which enables him to act, in so far as he can, as its master. It was strange that the last thing to be thought of should be his own personality, himself; the innermost workings of his soul. But if this profoundest problem has been neglected, it is to be neglected no longer. Psychology has {88} already made good its claim to be respectfully regarded as one of the sciences. It is too early to speak with any great certainty of the results that it has achieved, though these are probably more substantial than is commonly supposed. Anyhow, it will be best that, as before, we should give some characteristic statements of the investigators themselves, rather than attempt to make unauthorised summaries of our own. And, first of all, Sir Oliver Lodge shall tell us what he understands by the Soul. "The soul is that controlling and guiding principle which is responsible for our personal expression and for the construction of the body, under the restrictions of physical condition and ancestry. In its higher developments it includes also feeling and intelligence and will, and is the storehouse of mental experience. The body is its instrument and organ, enabling it to receive and to convey physical impressions, and to affect and be affected by matter and energy."[1] How the soul acts by means of the body is thus explained. "The brain is the link between the psychical and the physical, which in themselves belong to different orders of being."[2] {89} "A portion of brain substance is consumed in every act of mentation."[3] "Destroy certain parts of brain completely, and connexion between the psychic and the material regions is for us severed. True; but cutting off or damaging communication is not the same as destroying or damaging the communicator; nor is smashing an organ equivalent to killing the organist."[4]