Page:Principia Ethica 1922.djvu/183

V] confirmed or refuted by an investigation of causes and effects. It is, indeed, possible that some of our immediate intuitions are true; but since what we intuit, what conscience tells us, is that certain actions will always produce the greatest sum of good possible under the circumstances, it is plain that reasons can be given, which will shew the deliverances of conscience to be true or false.

91. (2) In order to shew that any action is a duty, it is necessary to know both what are the other conditions, which will, conjointly with it, determine its effects; to know exactly what will be the effects of these conditions; and to know all the events which will be in any way affected by our action throughout an infinite future. We must have all this causal knowledge, and further we must know accurately the degree of value both of the action itself and of all these effects; and must be able to determine how, in conjunction with the other things in the Universe, they will affect its value as an organic whole. And not only this: we must also possess all this knowledge with regard to the effects of every possible alternative; and must then be able to see by comparison that the total value due to the existence of the action in question will be greater. But it is obvious that our causal knowledge alone is far too incomplete for us ever to assure ourselves of this result, that an action is our duty: we can never be sure that any action will produce the greatest value possible.

Ethics, therefore, is quite unable to give us a list of duties: but there still remains a humbler task which may be possible for Practical Ethics. Although we cannot hope to discover which, in a given situation, is the best of all possible alternative actions, there may be some possibility of shewing which among the alternatives, likely to occur to any one, will produce the greatest sum of good. This second task is certainly all that Ethics can ever have accomplished: and it is certainly all that it has ever collected materials for proving; since no one has ever attempted to exhaust the possible alternative actions in any particular case. Ethical philosophers have in fact confined their