In this article I am not going to try and define introspection. I am going to try to state as precisely as possible how the practice of introspection can be improved, starting from the principle that there exists a disjunction between the logic of action and of conceptualization and the practice of introspection does not require that one should already be in possession of an exhaustive scientific knowledge bearing upon it. . To make matters worse, innumerable commentators upon what passes (...) for introspection do not seem to have practised it and have certainly never contributed anything to its development. My aim is therefore to bring to light a procedure for progressive improvement in the practice of introspection when it is employed in a programme of research. (shrink)