A great deal of the moral philosophy

For Schueler:

A great deal of the moral philosophy of the last hundred years has been devoted to trying to understand “the relation between ‘is’ and ‘ought’. On the one side, when we are engaged in genuine moral reasoning and debite, we seen to take it for granted that various factual claims support judgments about we ought or ought not to do. We even seem to regard some such judgments as true (and othres as false). On the other side, when we reflect on such judgments, it seems difficult indeed to see how either of these things could be straightforwardly the case, in view of the very great difference between factual and evaluative (or normative) judgments (1995, p. 713)

We must to face the challenge formulated by Poincaré since 1902 according to which there's a distinction between theory, best known as knowledge about the facts, and the ethics, that prescribes to anybody what ought to be.

Whereas theoretical propositions are based on normal logic, that deals with the truthfunctional values, and ethical propositions are not based on normal logic, there exists the following open question: what logic for all those reasonings that don't use the classic logic, that's truthfunzional?

Notes

G. F. Schueler (1995), Why “oughts” are not Facts (or What the Tortoise and Achilles Taught Mrs. Ganderhoot and Me about Practical Reason), “Mind”, 416, pp. 713 – 723.

(immagine tratta da: http://upload.wikimedia.org/wikipedia/commons/thumb/a/af/JH_Poincare.jpg/220px-JH_Poincare.jpg)