Eugen Rosenstock-Huessy's *In the Cross of Reality,* the first volume of his *Sociology*:
"Rene Descartes' mother died shortly after childbirth. . . . He never found relief from the formal strictness prevalent among grown men, with its presumption of standing by one's given world. Prematurely, this child had no choice but to take a stand. But where no mother's lap exists . . . the motherless child must try as calmly and imperturbably as possible to learn to stand" (281-2). Later he calls the Cogito a "deep sigh" from a man characterized by the "boyish seriousness of the unprotected, seeking safety in his thought so that he will not be laughed at" (287).
Rosenstock-Huessy is contrasting Descartes to Nietzsche, whose father died when he was 5.
He thinks this two form the bookends of modern philosophy, from motherless Cartesianism to fatherless nihilism.