In this paper I sketch a reconstruction of the basic psychoanalytic conception of the mind in terms of two historical resources: the conception of the subject developed in post-Kantian idealism, and Spinoza's laws of the affects in Part Three of the Ethics. The former, I suggest, supplies the conceptual basis for the psychoanalytic notion of the unconscious, while the latter defines the type of psychological causality of psychoanalytic explanations. The imperfect fit between these two elements, I claim, is reflected in familiar conceptual difficulties surrounding psychoanalytic theory and explanation.