Treatise on the Three Impostors: Moses, Jesus, Mohammed

The Treatise on the Three Impostors was first published in 1712 under the
title L'esprit de M. Benoît de Spinosa, preceded by a biography entitled La
Vie de M. Benoît de Spinosa. These two works, of very dissimilar contents,
have been brought together only by their common reference to Spinoza. Who is
the author? This question has lost none of its relevance in three centuries.
First of all, let us rule out the participation of Spinoza himself for
chronological reasons, La vie de M. Benoît de Spinosa refers to events after
the philosopher's death in 1677, such as the presence of the Prince of Condé
in Utrecht, "at the beginning of the last wars" in 1678. In his Dictionnaire
Historique, published in The Hague in 1758, Prosper Marchand concluded that
the author of L'esprit de M. Benoît de Spinosa was a certain Jan Vroesen.
Marchand was a scholar, editor, bibliographer, bookseller and writer, and one
of the most knowledgeable figures on the movement of ideas and authors in
Northern Europe. If we confine ourselves to this information, however, we
might be embarrassed. Indeed, if he is indeed the complete and only author of
L'esprit de M. Benoît de Spinosa, Vroesen must have been a very precocious
man, since around 1687, Vroesen was only fifteen or sixteen years old. Until
the French Revolution, literate Europe was full of memoirs, hypotheses and
questions about the real author of the Treatise of the Three Impostors. People
even came to suspect Frederick II of Prussia, a notorious anticleric, of being
its author. The only problem is that Frederick was born the same year that the
Rotterdam edition was published.