“My own interpretation of the question may be put in this way. The thing that is given in nature is a process in time. According to its complexity and degree of co-ordination an organic process has different degrees of awareness. There is no one condition called human consciousness, because the human organism can function with different degrees of co-ordination, and if we ask if an atom in absorbing light is conscious, the question has no definite meaning. But in a few years those who are studying the physiology of the central nervous system will be able to indicate how many steps of synthesis and integration occur between the simplest cell and the creative thinker, and to each of these stages will be ascribed a mode of awareness. But below a certain degree of organic complexity this ‘awareness’, will cease to be anything that can be consciously imagined by man, e.g. below the dimmest sentience one might allow an undifferentiated knowledge of mere continuance, based in turn on the rhythmic pulsation of the elementary cells.” “Your scheme is of course still rather vague, but in its main outlines it appears satisfactory”, replies the psychologist. “But tell me outright, can mind influence matter? If I understand you rightly, you suggest that matter certainly influences mind.” “On the contrary, I do not! You are back at the meaningless questions on which philosophers have wasted much time. To ask if mind can influence matter does not mean anything until you know what you mean by mind and matter, and to a scientist that means knowing the laws they obey. Now, on the one hand, relativity and modern quantum theory indicate that there is no matter in the old sense of particles made of some unchanging stuff, and physical science recognizes atomic and other _processes_ as fundamental in the place of ‘matter’. On the other hand, you really mean by ‘mind’ one particular form of conscious activity: the deliberate selection of a purpose. Therefore to give your question real meaning I have to ask instead ‘Does the conscious selection of a purpose alter the physical processes going on in the human organism?’ “But that is an absurd question. It is like asking: Does a dint in the outside of a hat _cause_ an alteration in the shape of the inside of the hat? To which the only reply is that the dint on the outside is merely another way of describing the dint on the inside. There is no _causing_ of the one by the other any more than if you fold a bit of paper you can say that the crease on one side causes the crease on the other side. They are identical and the double method of description used in the question creates a meaningless problem.