We believe with the publication of our Lexicon Spinozanum, that we are meeting a need in Spinoza historiography which has been pointed out by scholars, but has never before been satisfied. In the intro duction of his Spinozas philosophische Terminologie (Leipzig, 1913), G. T. Richter promised "a Spinozistic Lexicon in which the meaning of each term is set out on an historical basis in alphabetical order". In 1924, in the Report, i.e., Nachbericht, of his four volume edition of the complete works of Spinoza (Heidelberg), C. Gebhardt promised a complementary volume comprising, among other things, a general index. However, neither the one nor the other were ever published. The hope of seeing this gap quickly filled has been reiterated recently by Di Vona: "The compilation of a Spinozistic index is a task of the history of philosophy, the execution of which would gratify all scholars". (Di V on a, Studi suIt' ontologia di Spinoza, Florence, 1960). We do not know how closely our Lexicon Spinozanum corresponds to what Richter and Gebhardt projected. We believe, however, that there are common requirements at the basis of works of this sort. In our procedure and in the delimitation of our scope, we have set for ourselves two main criteria: that of clarity and that of completeness. We hope we hav:e not deviated from them too much.