“The analysis of instinct from a purely physiological point of view ultimately furnishes the data for a scientific ethics. Human happiness is based upon the possibility of a natural and harmonious satisfaction of the instincts.... It is rather remarkable that we should still be under the influence of an ethics which considers the human instincts in themselves low and their gratification vicious. That such an ethics must have had a comforting effect upon the orientals, whose instincts were inhibited or warped through the combined effects of an enervating climate, despotism and miserable economic conditions is intelligible, and it is perhaps due to a continuation of the unsatisfactory economic conditions that this ethics still prevails to some extent.... Lawyers, criminologists and philosophers frequently imagine that only want makes man work. This is an erroneous view. We are instinctively forced to be active in the same way as ants or bees. The instinct of workmanship would be the greatest source of happiness if it were not for the fact that our present social and economic organization allows only a few to satisfy this instinct. Robert Mayer has pointed out that any successful display or setting free of energy is a source of pleasure to us. This is the reason why the satisfaction of the instinct of workmanship is of such importance in the economy of life, for the play and learning of the child, as well as for the scientists or commercial work of the man.... We can vary at will the instincts of animals. A number of marine animals ... go away from the light, can be forced to go to light in two ways, first by lowering the temperature and second by increasing the concentration of the sea water, whereby the cells of the animals lose water. This instinct can be again reversed by raising the temperature or by lowering the concentration of the sea water. I have found repeatedly that by the same conditions by which phenomena of growth and organization can be controlled the instincts are controlled also. This indicates that there is a common basis for both classes of life phenomena. This common base is the physical and chemical character of the mixture of substances which we call protoplasm.... _The greatest happiness in life_ can be obtained only if _all instincts_, that of workmanship included, can be maintained at a certain _optimal intensity_. But while it is certain that the individual can ruin or diminish the value of its life by a onesided development of its instincts, e.g., dissipation, it is at the same time true that the _economic and social conditions can ruin or diminish the value of life for a great number of individuals_. It is no doubt true that in our present social and economic conditions more than ninety per cent