For to be possessed of a vigorous mind is not enough; the prime requisite is rightly to apply it. - René Descartes

There is no need to allege that Descartes sat in or on a stove. A poêle is simply a room heated by an earthenware stove. Cf. E. Gilson, Discours de la méthode: texte et commentaire, 4th edition (Paris: Vrin, 1967), p. 157.

My third maxim was to endeavour always to conquer myself rather than fortune, and change my desires rather than the order of the world, and in general, accustom myself to the persuasion that, except our own thoughts, there is nothing absolutely in our power;

while I wanted thus to think that everything was false, it necessarily had to be the case that I, who was thinking this, was something. And noticing that this truth — I think, therefore I am — was so firm and so assured that all the most extravagant suppositions of the skeptics were incapable of shaking it, I judged that I could accept it without scruple as the first principle of the philosophy I was seeking.