I have finished Russell's Nightmares and must confess that they did not come up to expectation. No doubt it was my fault for expecting too much, knowing how unsatisfactory I find his philosophical views; but I had hoped that, at least, when he was not writing normal philosophy, he would be entertaining. Alas! I found his wit insipid, and his serious passages almost intolerable—there was something of the embarrassment of meeting a Great Man for the first time, and finding him even more preoccupied with trivialities than oneself.In his Introduction, Russell says 'Every isolated passion is, in isolation, insane; sanity may be defined as a synthesis of insanities', and then he proceeds to give us examples of isolated insanities—the Queen of Sheba as Female Vanity, Bowdler as Prudery, the Psycho-Analyst as Social Conformity, and so on. Amongst these, as you noted, is the Existentialist as Ontological Scepticism. Here, Russell's satire is directed partly against what Sartre has called 'a literature of extreme situations'; and this, for an Englishman, is no doubt a legitimate target, since the English do not admit that there are such things—though, of course, this makes the English a target for the satire of the rest of Europe, particularly the French.But what Russell is not entitled to do is to group the insanity of doubting one's existence along with the other insanities, and this for the simple reason that it precedes them. One may be vain or modest; one may be prudish or broadminded; one may be a social conformist or an eccentric; but in order to be any of these things, one must at least be. The question of one's existence must be settled first—one cannot be insanely vain if one doubts whether one exists at all and, precisely, Russell's existentialist does not even succeed in suffering—except when his philosophy is impugned (but this merely indicates that he has failed to apply his philosophy to itself, and not, as Russell would have us believe, because he has failed to regard his philosophy in the light of his other insanities). The trouble really is, that Russell does not, or rather will not, admit that existence poses a problem at all; and, since he omits this category from all his thinking nothing he says concerns anybody in particular.