 Besides, although Mersenne’s “scientific apologetics” was primarily conceived as a defense of religion against “atheists”, where science is only a tool, it turned out to be also a defense of mathematical sciences against whoever might think that they are vain curiosity and must be either rejected, or at least relativized as inessential knowledge… This is especially manifest in the later works, where Mersenne gave free rein to his passion for mathematical sciences. Whereas natural theology and anti-deistic polemic were no longer dominant themes, he still vindicated the “usefulness” of mathematics, not only for men’s welfare, but for their edifying virtues. In the next decades, one could find similar moves in defense of the “usefulness of natural experimental philosophy” in the works of Robert Boyle.