[Undated] Theories for Use in the Psychoanalysis of Disorders of Thought. Cogitations

The scientific principles on which this book [a preliminary outline of Learning from Experience] is planned I have explained elsewhere. But it may not be out of place to summarize the main points for the benefit of those to whom this form of presentation is unusual. First, a warning: the reader may feel that what is said is obscure and difficult.1 Allowing for the intrinsic difficulties of the subject, I believe that much of what is felt to be obscure on a first reading will appear less so if the reader will not allow himself to dwell too long on his first encounter with an obscurity, but will press on till the end, when I think he will have a fair idea of the whole and will thus be in a position to return to the earlier obscurity to find it much more comprehensible. But of course I realize that ultimately the difficulties of the subject, and my limitations in exposition, will make the value of the book depend very much on the skill and patience of the reader, and the goodwill with which he repairs the deficiencies of my work. I can at least promise that he is not being called on to waste his time because I have grudged mine.

The first part of the book consists of theories. Each theory is set out on the same plan, which is essentially that of a scientific deductive system. That is to say, first there are a number of hypotheses so arranged that they follow logically from the premises and from the preceding hypotheses. Consequently each hypothesis has a preceding premise, and is itself the premise of a succeeding hypothesis.

This system is in accord with that pursued by those sciences, particularly physics and mathematics, whose success both in results