Considering that we have to spend the whole of our lives in this human machine, considering that it is our sole means of contact and compromise with the rest of the world, we really do devote to it very little attention. When I say 'we,' I mean our inmost spirits, the instinctive part, the mystery within that exists. And when I say 'the human machine' I mean the brain and the body - and chiefly the brain. The expression of the soul by means of the brain and body is what we call the art of 'living.' We certainly do not learn this art at school to any appreciable extent. At school we are taught that it is necessary to fling our arms and legs to and fro for so many hours per diem. We are also shown, practically, that our brains are capable of performing certain useful tricks, and that if we do not compel our brains to perform those tricks we shall suffer. Thus one day we run home and proclaim to our delighted parents that eleven twelves are 132. A feat of the brain! So it goes on until our parents begin to look up to us because we can chatter of cosines or sketch the foreign policy of Louis XIV. Good! But not a word about the principles of the art of living yet! Only a few detached rules from our parents, to be blindly followed when particular crises supervene. My aim is to direct a man's attention to himself as a whole, considered as a machine, complex and capable of quite extraordinary efficiency, for travelling through this world smoothly, in any desired manner, with satisfaction not only to himself but to the people he meets en route, and the people who are overtaking him and whom he is overtaking. My aim is to show that only an inappreciable fraction of our ordered and sustained efforts is given to the business of actual living, as distinguished from the preliminaries to living.