It is an actual relief to many, this repose of attention, this extinction of the will which steals over us in the midst of life’s troubles, lifting the burden of care and allowing us to contemplate quietly the curious spectacle which, when left to itself, the brain at work presents. How rapidly things and thoughts are transformed, melting into each other without order, aim, or pause! How easily we glide by winding paths through time and space, while in endless succession new horizons and new countries rise before us! What airy phantoms look down from the clouds above, what voices and harmonies strike the ear in the waterfalls of the brooks, what living pictures peer at us from amongst the flowers and grasses on the bank! Then suddenly a flood of memories rushes over us and leaves us confused, bewildered, as it rolls on again to the dim horizon of consciousness. And in this rushing flood of thoughts and forms we see the familiar faces of those whom the grave seems to give back to us, and we hasten to meet them with smiling lips or with tears in our eyes. II And yet these are nought but dreams of the waking mind. Even when the force of attention and the energy of thought are greater, we still are carried away by the wilful, untamable current of cerebral activity; because the will can do nothing within the domain of the imagination, and because the brain is no slave who will obey our very nod. Who does not remember the painful and useless endeavours made to rid oneself of an annoying thought and that incapacity for mental work which afflicts us, without our knowing whence it came? How often have we sat for hours at the desk, with idle pen, our head in our hands, unable to wrest even one thought from the mind which we dared transmit to paper! How depressed we are on those days when the sources of the mind seem dried up, when we torture ourselves in vain, ransacking our brains and finding nothing but fragments, crumbs of thought which we reject angrily as worthless refuse! We must resign ourselves. We feel ourselves humbled as though the door of our own house had been shut in our face. It is of no use to be sad and annoyed; even if we give way to furious passion, it does not help us. We stand behind a high wall which we cannot break down. An English physiologist compared the thinking man to a simple engine-driver. He does not move the trains, neither does he determine their departure or their stoppage, he merely guides their movement, directing them first in one direction then in another.