S. T. Joshi summarizes Lovecraft’s vision:
Humanity is not at centre stage in the cosmos, and there is no one to help us against the entities who have from time to time descended upon the earth and wreaked havoc; indeed, the ‘gods’ of the Mythos are not really gods at all, but merely extraterrestrials who occasionally manipulate their human followers for their own advantage.
Samuel Francis, writing in the May 1997 issue of Chronicles: A Magazine of American Culture, offers his own take:
Mr. Joshi is correct about the cosmic level of meaning in Lovecraft’s stories, but he largely neglects another, social level of meaning. On that level, Lovecraft’s stories are dramas of modernity in which the forces of tradition and order in society and in the universe are confronted by modernity itself — in the form of the shapeless beings known (ironically) as the “Old Ones.” In fact, they are the “New Ones.” Their appearance to earthly beings is often attended by allusions to “Einsteinian physics,” “Freudian psychology,” “non-Euclidean algebra” (a meaningless but suggestive term), modern art, and the writing of T.S. Eliot and James Joyce. The conflicts in the stories are typically between some representative of traditional order (the New England old stock protagonist) on the one hand, and the “hordes” of Mongoloids, Levantines, Negroes, Caribbeans, and Asians that gibber and prance in worship of the Old Ones and invoke their dark, destructive, and invincible powers.
What Lovecraft does in his stories, then, is not only to develop the logic of his “cosmicism” by exposing the futility of human conventions, but to document the triumph of a formless and monstrous modernity against the civilization to which Lovecraft himself — if almost no one else in his time — was faithful. In the course of his brief existence, he saw the traditions of his class and his people vanishing before his eyes, and with them the civilization they had created, and no one seemed to care or even grasp the nature of the forces that were destroying it. The measures conventionally invoked to preserve it — traditional Christianity, traditional art forms, conventional ethics and political theory — were useless against the ineluctable cosmic sweep of the Old Ones and the new anarchic powers they symbolized.
Lovecraft believed that his order could not be saved, and that in the long run it didn’t matter anyway, so he jogged placidly and cynically on, one of America’s last free men, living his life as he wanted to live it and as he believed a New England gentleman should live it: thinking what he wanted to think, and writing what he wanted to write, without concern for conventional opinions, worldly success, or immortality. And yet, despite the indifference he affected, Howard Phillips Lovecraft has in the end attained a kind of immortality, for the classic tales of horror he created will be read as long as that genre of literature is read at all.
(Hat tip to Bradlaugh at Secular Right who correctly notes that Lovecraft is more fun to read about than he is to read.)