ABSTRACT
Intellectual progress is by no one trait so adequately characterized, as by development of the idea of causation; since development of this idea involves development of so many other ideas. The conception of natural causation is so imperfectly developed, that there is only an indistinct consciousness that throughout the whole of human conduct, necessary relations of causes and effects prevail; and that from them are ultimately derived all moral rules, however much these may be proximately derived from moral intuitions. Conduct, according to its theory, is to be estimated by observation of results. Ethics has a physical aspect; since it treats of human activities which, in common with all expenditures of energy, conform to the law of the persistence of energy: moral principles must conform to physical necessities. It has a psychological aspect; for its subject-matter is an aggregate of actions that are prompted by feelings and guided by intelligence.
