From the letter to Mersenne, 25 December 1639

. . . 10. I have noticed that Lord Herbert takes many things as common notions which are nothing of the kind. It is certain that nothing should be taken as such unless it cannot be denied by anybody.

I turn to your letter of 4 December and thank you for the advice you give me about my essay on Metaphysics. The arguments of Raymond Lull are sophistries which I do not take seriously. As for the objections of your Analysts, I shall try to solve them without setting them out; that is, I shall lay the foundations, from which those who know the objections to them may derive their solution, without teaching them to those who have never heard of them. I think this how one should treat the matter. In any case, I am not so short of books as you think; I have here a Summa of St. Thomas and a Bible which I brought from France.

SOURCE: Descartes to Mersenne, 25 December 1639 [excerpt], in: Descartes: Philosophical Letters, translated and edited by Anthony Kenny (Oxford: Clarendon Press, 1970), pp. 68-69.

Note: In the letter to Mersenne of 13 November 1639, “Analysts” refers to the geometers of Paris.

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