_Written in England while impatiently waiting to get back to France. Professor Bateman had been recalled from the trenches, where he was sergeant, to become major of the Western Universities' Battalion, and then was forced to wait in England after this unit was broken up, while in France his former battalion was preparing for Vimy. This letter was written shortly after its capture._ April 29th, 1917. Dear J. V., "Letter received and contents noted." I can understand how you feel about Maunsell's death. Personally, I have long ago given up theorizing about what may or may not be at the back of phenomena. I confine myself to what I can see and know and reason about, and I find that I have quite as much as I can handle even in that narrow sphere. Once one gets into the region of the supernatural, one man's dream or speculation is just as good or as worthless as another's, for neither has any foundation in experience, and experience gives us our only possible basis for the construction of theories about life. So, though you may allow your thoughts at times to get out of hand and wander about gropingly in a nebulous unknown, you ought not to allow any baseless theories that result to disturb your peace of mind. If you attach any importance to such propositions about the unknown, you can find plenty of comforting ones evolved by greater brains than yours, which you would do better to accept than allow yourself to be worried and made less effective for the business of life by the pessimistic result of your own thinking. Constant brain work has a tendency to make a man morbid in his speculations. A free, open-air life, practical problems and contact with men who do things rather than theorize about them is a great corrective. No one yet has gone anywhere near solving the riddle of the unknown, and it may fairly be supposed that the human brain is at present incapable of tackling the problem successfully. It may be that the perpetual struggle after a solution may, in ages to come, result in the evolution of a brain which can find an answer to the riddle of life, in the same way as the constant reaching of the giraffe after food resulted in the production of a neck sufficiently long to solve the giraffe's food problem. Meantime, we must be content to get along with such knowledge as we have, or else accept a supernatural revelation which is bound at the best to be a bit dim and unsatisfactory, because it is communicated to us by means of the same imperfect brain.