NOTE ON THE PHILOSOPHY OF .A SUPPOSITION. 503 suppositions teleologically is that the construction and the de- velopment of the ideal content of the supposition is determined throughout by the end it subserves, whether that end be imma- nent or extrinsic. This appears if each of the classes mentioned is considered a little more closely. First, as to suppositions that have as their end the good, or, what are called here, practical suppositions ; a supposition framed for the guidance of conduct is an ideal forecast of the result of following a certain line of action. Out of this arises one great limitation that attaches to practical suppositions : they deal only with the future. Practical thought so far as it is practical never looks back. The irrevocableness of the past makes thought about the past speculative, not practical. The moving finger writes and, having writ, Moves on. Nor all your piety nor wit Can lure it back to cancel half a line, Nor all your tears wash out a word of it. Eegrets are vain things ; from the point of view here in question, that is final. The tears that are shed over spilt milk are idle tears, though it may well be that, from the speculative point of view, their uselessness is an added sorrow. The future is the province of practical suppositions, but within this province practical supposi- tions are further circumscribed by a limitation that makes the area proper to them but a small part of the future. The aspect, under which they regard the future, is the future as it can bs controlled or modified by the agent. Man can enter into the future as an influence of change only along the lines of the practicable, and in relation to a given man, at a given moment, the lines open must ever be very limited. About the impracticable there is no delibera- tion, and this limitation attaches to the suppositions under consid- eration, as forming part of the mechanism of deliberation. Looking along the lines of action open to him, the agent in reflective choice may go over the possibilities, and say to himself, If I do this, the results will be so and so ; if I do that, the results will be so and so. This is the formula according to which such suppositions are made. When the suppositions are allowed to develop into their results, the agent may guide himself, wholly or partially, by the contemplated results, as to which supposition he will make actual. In determining practical judgment the development of each sup- position will have value according to its reality and comprehen- siveness. Games of skill illustrate well the function of a practical supposi- tion. In a game of chess, for instance, the player has his choice of a certain limited number of moves. So far as it is rational, his choice is determined by forecasting the results of each move and making the move that promises best. There is a struggle for existence, as it were, amongst the possibilities, the possibility finally actualised is reached through a series of rejected supposi- tions. The framing, developing, and valuing of the supposition in
