A laborious reconstruction of a primitive and simple truth which the philosopher could not, for a single moment, have banished from his mind all the while that he was laboring painfully to demonstrate it.
By a tacit avowal of the weakness of the human mind, the speculations of Descartes stopped short at death.

He had hopes, however, of retarding the moment of it.

"I felt myself alive," he said, at forty years of age, "and, examining myself with as much care as if I were a rich old man, I fancied I was even farther from death than I had been in my youth." He had yielded to the entreaties of Queen Christina of Sweden, who had promised him an observatory, like that of Tycho Brahe.

He was delicate, and accustomed to follow a regimen adapted to his studies.

"O flesh!" he wrote to Gassendi, whose philosophy contradicted his own: "O idea!" answered Gassendi.