Genetic psychology is dominated by the figure of Piaget, and a philosopher cannot begin to give his comments on the subject without a certain diffidence, as the great man's scathing and uncomplementary remarks about philosophers ring in his ears. So I would like to say something in expiation or extenuation for the lines which follow. The kind of reflection which can be called philosophical cannot simply precede empirical discovery and lay out the field of the possible and the impossible. It can only be a reflection on empirical findings, raising questions about their interpretation, about the connections between them, about the problems they raise or help to solve. In this sense, ‘philosophy’ shades into the kind of reflection and discussion which any innovative empirical scientist must engage in. It can only be distinguished, if at all, in that we like to reserve the term for questions about the more fundamental issues. But wherever one draws the line, I believe that there is a perfectly defensible sense in which one can speak of the philosophical views and ideas of Piaget. And it is in this sense, I believe, that a philosophical reflection on genetic psychology might be useful, even if it loses greatly in value in not being based on the degree and scope of empirical knowledge which searchers in the field have at their disposal.

What is genetic psychology? The term might be reserved for a certain field within psychology, that containing all questions to do with ontogenesis.