So far as I know myself, after making due deduction for the ambition of youth and a fiery temper, which ought to (but unfortunately does not) get cooler with age, my sole motive is to get at the truth in all things. I do not care one straw about fame, present or posthumous, and I loathe notoriety, but I do care to have that desire manifest and recognised. Your paper deals with a problem which has profoundly interested me for years, but which I take to be insoluble. It would need a book for full discussion. But I offer a remark only on two points. The doctrine of the conservation of energy tells neither one way nor the other. Energy is the cause of movement of body, i.e. things having mass. States of consciousness have no mass, even if they can be conceded to be movable. Therefore even if they are caused by molecular movements, they would not in any way affect the store of energy. Physical causation need not be the only kind of causation, and when Cabanis said that thought was a function of the brain, in the same way as bile secretion is a FUNCTION of the liver, he blundered philosophically. Bile is a product of the transformation of material energy. But in the mathematical sense of the word "function," thought may be a function of the brain. That is to say, it may arise only when certain physical particles take on a certain order. By way of a coarse analogy, consider a parallel-sided piece of glass through which light passes. It forms no picture. Shape it so as to be bi-convex, and a picture appears in its focus. Is not the formation of the picture a "function" of the piece of glass thus shaped? So, from your own point of view, suppose a mind-stuff--logos---a noumenal cosmic light such as is shadowed in the fourth gospel. The brain of a dog will convert it into one set of phenomenal pictures, and the brain of a man into another. But in both cases the result is the consequence of the way in which the respective brains perform their "functions." Yet one point. The actions we call sinful are as much the consequence of the order of nature as those we call virtuous. They are part and parcel of the struggle for existence through which all living things have passed, and they have become sins because man alone seeks a higher life in voluntary association. Therefore the instrument has never been marred; on the contrary, we are trying to get music out of harps, sacbuts, and psalteries, which never were in tune and seemingly never will be. Ever yours very faithfully, T.H. Huxley. [Few years passed without some utterance from Huxley on the subject of education, especially scientific education. This year we have a letter to Professor Ray Lankester touching the science teaching at Oxford.] Hodeslea, Eastbourne, January 28, 1891. Dear Lankester,