The general error in theory on this subject lies in a misconception of the idea of "adjustment" to environment, the fact not being noted that the environment is not itself fixed and permanent. What the environment is depends upon the nature and faculties of the individual, the same environment being a different one for amoeba and human being, for the blind man and the man possessing sight; and what environment is and what the individual does are settled at one and the same time, the process of selection being one from both sides, and the variation of both. The adaptation "wherever it exists and so far as it exists" is, hence, perfect adaptation; if the lower organism is adapted to its environment, its adaptation is as perfect as that of the higher organism to its environment. Every successful life means adaptation. "Every animal which can maintain its life is in adaptation to its environment." The bare formula of adaptation means nothing more than the fact of existence. "Adaptation to the conditions as such teaches us nothing as to the nature of the organism; for all functions are reactions upon the conditions, and therefore, so far, adaptations. But it points to something behind. It means that _all_ the functions of the animal are adapted to the conditions, and this means that its functions are adapted or adjusted to one another under the conditions." "The moral ideal consists in a certain equilibrium established on the basis of certain conditions--wants and sentiments in moral agents." It involves advance just for this reason, because the act of adjustment implied in good conduct itself alters the sentiments of the agent, and creates new needs demanding a new satisfaction. The change is not always in the same direction, however; for cultivation in one direction may cause the individual to become aware of capacities or wants in quite another direction, or the advocacy of one side of a question, persevered in, may so open up the other side as to end in complete change of view. In any case, however, there is an enlargement of experience, and the old facts are themselves changed by it as well as are the individuals subject to it.