Above all, because including all, the century will ask for men of sober mind. The finest piece of mechanism in all the universe is the brain of man and the mind which is its manifestation. What mind is, or how it is related to brain cells, we cannot say, but this we know, that as the brain is, so is the mind; whatever injury comes to the one is shown in the other. In this complex structure, with its millions of connecting cells, we are able to form images of the external world, truthful so far as they go, to retain these images, to compare them, to infer relations of cause and effect, to induce thought from sensation, and to translate thought into action. In proportion to the exactness of these operations is the soundness, the effectiveness of the man. The man is the mind, and everything else is accessory. The sober man is the one who protects his brain from all that would do it harm. Vice is our name for self-inflicted injury, and the purpose of vice is to secure a temporary feeling of pleasure through injury to the brain. Real happiness does not come through vice. You will know that which is genuine because it makes room for more happiness. The pleasures of vice are mere illusions, tricks of the nervous system, and each time these tricks are played it is more and more difficult for the mind to tell the truth. Such deceptions come through drunkenness and narcotism. In greater or less degree all nerve-affecting drugs produce it; alcohol, nicotine, caffeine, opium, cocaine, and the rest, strong or weak. Habitual use of any of these is a physical vice. A physical vice becomes a moral vice, and all vice leaves its record on the nervous system. To cultivate vice is to render the actual machinery of our mind incapable of normal action. It is the brain's business to perceive, to think, to will, to act. All these functions taken together we call the mind. The brain is hidden in darkness, sheltered within a box of bone. All that it knows comes to it from the nerves of sense. All that it can do in this world is to act on the muscles it controls through its nerves of motion. The final purpose of knowledge is action. Our senses tell us what lies about us, that we may move and act, and do this wisely and safely. The sense-organs are the brain's only teachers so far as we know, the muscles are its only servants. But there are many orders which may be issued to these servants. Out of the many sensations, memories, imaginations, how shall the brain choose?