Starting from merely theoretical considerations, Kant defines pleasure as a feeling of furtherance, pain, as a feeling of hindrance of life; and so prominent a physiologist and psychologist as Alexander Bain says that “States of pleasure are connected with an increase, states of pain, with an abatement of some or of all the vital functions.” A consideration of the actual causes of our pleasures and pains will prove the incorrectness of these views, which are also due to wrong generalisations. An increase of the vital functions and a further growth, either of the organs or of the whole organism, is very often accompanied with pain. A growing tooth causes, as a rule, as much pain as a decaying tooth. And if by some drug the decay is hastened and the nerve is killed, there is, connected with the suppression and sometimes with the mere abatement of the vital function, an abatement of the pain also. Feelings of pleasure and pain presuppose that habits have been formed in a sentient organism. Pain is not always a hindrance of life, nor is every hindrance of life painful. Pain is not an abatement of the functions of life, not a decay, nor a destruction. But pain is always a disturbance of life and of the habits that have been formed. Growth is, under certain circumstances, as much a disturbance as is decay. And decay, if it is simply an abatement or cessation of function, is not accompanied with pain. While pain is always a disturbance of the functions of an organism, pleasure is simply the gratification of wants; functions and wants being formed by habits, we may briefly say that pleasure is agreement, pain disagreement, with habits. There are natural wants and unnatural wants. There are habits beneficial to the furtherance of life, and there are habits injurious to the furtherance of life. The pleasure connected with the gratification of wants does not depend on its being a furtherance or a hindrance of life, but solely on the intensity of the want. And the intensity of the want, again, depends on the degree to which a habit has become inveterate.[43] * * * * * The theory of pleasure and pain which regards pleasure as indicative of the growth, and pain, of the decay of life, leads ultimately to the ethics of hedonism, which identifies the good with the pleasurable. However, if our view of pleasure and pain be correct, it is apparent that the pleasure theory in ethics is wrong in its very foundation. The pleasurable would cease to be a criterion of goodness; for many things are pleasurable that are bad, and many things are painful that are good. Growth, development, progress, evolution have often been, nay must mostly be bought with great pain, tribulation, anxiety, and also with the renunciation of pleasures. On the other hand the fulness of pleasure is always a very dangerous symptom for any state of existence.