Lovecraft was born August 20, 1890, in Providence, Rhode Island, at the home of his maternal grandfather, Whipple V. Phillips, a prosperous industrialist and New England gentleman who was the dominant intellectual influence on his grandson's early life, both personally and through his extensive library of works by eighteenth-and nineteenth-century authors. Of the Victorian mansion on Angell Street, Lovecraft wrote: "Here I spent the best years of my childhood. The house was a beautiful and spacious edifice, with stable and grounds, the latter approaching a park in the beauty of the walk and trees." A precocious child whose delicate health allowed him only sporadic attendance at school, Lovecraft flourished in a world of cultured adults who fostered his interest in Greco-Roman antiquity, astronomy, eighteenth-century literature and history, and Gothic tales of terror. This milieu, and the traditions on which it was founded, served as the prime mental and emotional coordinates of Lovecraft's life, whose auspicious beginnings gradually devolved into a lethargic procession of loss and unfulfilled promise: Lovecraft's father, a handsome, syphilitic traveling salesman who was effectively a stranger to his son, died in 1898 after spending the last five years of his life institutionalized with general paresis; Lovecraft's grandfather died in 1904, and subsequent ill-management of his financial holdings forced Sarah Phillips Lovecraft and her only child to move from their family home into a nearby duplex. In his published letters, Lovecraft unfailingly celebrates his mother's refinement and cultural accomplishments; in biographies of Lovecraft, his mother is portrayed as an intelligent and sensitive woman, a neglected wife, and an overprotective parent who instilled in her son a profound conviction that he was different from other people.

In 1908 Lovecraft suffered a nervous breakdown that prevented his attaining enough credits to graduate from high school, and, rather than entering Brown University to pursue the professorship that he had formerly assumed would occupy the rest of his life, he continued his program of self-education. During this period Lovecraft in large part existed as a semi-invalid recluse. In 1914 his isolation was alleviated when he joined the United Amateur Press Association, a group of nonprofessional writers who produced a variety of publications and exchanged letters. A voluminous writer from an early age, Lovecraft now directed his efforts toward these amateur journals, with his own magazine, the Conservative, appearing from 1915 to 1923. He also became involved in a network of correspondence which for the rest of his life provided a major outlet for personal and artistic expression. In these letters, Lovecraft discussed an encyclopedic range of subjects in essay-like length and depth; here he also vented his lifelong obsessions, most prominently his love of the past and of scientific truth, and his aversion to the modern world and to all peoples who were not of the Anglo-Nordic cultural stream, although several biographers maintain that he moderated some of his extremist views later in his life. Lovecraft's contributions to amateur journals were almost exclusively in the form of poems and essays, the former being imitations of such eighteenth-century poets as Alexander Pope and James Thomson, and the latter displaying a style strongly influenced by such eighteenth-century prose writers as Joseph Addison and Samuel Johnson. Although Lovecraft wrote several horror stories after his first reading in 1898 of the tales of Poe, he destroyed most of these efforts and wrote no fiction from 1908 to 1917. In the latter years he was encouraged by editor W. Paul Cook to resume fiction writing, resulting in the successive composition of "The Tomb" and "Dagon," the first of what are considered Lovecraft's mature works. After further encouragement from other friends, these two stories, along with three others, were submitted to the pulp magazine Weird Tales, which afterward became the principal publisher of Lovecraft's fiction during his lifetime.

Beginning around 1919, Lovecraft began to socialize with other amateur journalists, and through these channels in 1921 he met Sonia H. Greene, a Russian Jewish business-woman from New York City. They married in 1924 and Lovecraft went to live with his wife in New York, where he hoped to find employment that would enable him to abandon the disagreeable and insubstantial living he previously earned as a literary reviser and ghostwriter. Ten months later the couple separated for reasons that Lovecraft described as largely financial, although the situation was aggravated by Lovecraft's hatred of a city with such a conspicuously mixed racial and ethnic population. In 1926, Lovecraft returned to Providence, where he lived for the remainder of his life. To supplement his dwindling inheritance he was forced to continue his revision work. Despite his nearly destitute financial state, Lovecraft managed to travel extensively, documenting these excursions in his letters and in such essays as "Vermont: A First Impression," "Charleston," and A Description and Guide to the City of Quebeck. During the last ten years of his life, he also produced what are considered his greatest works, including "The Call of Cthulhu," The Case of Charles Dexter Ward, "The Colour out of Space," "The Shadow over Innsmouth," and At the Mountains of Madness. Lovecraft died of intestinal cancer March 15, 1937, at the age of forty-six.

While an account of the outward events of Lovecraft's life may suggest some of the character traits that critics have found immensely valuable in explicating his works, it fails to convey the full range and intensity of his convictions, preoccupations, and eccentricities. As revealed in his letters, Lovecraft's most important experiences were those of a self-sustaining and isolated imagination. The solitary worlds that he inhabited in childhood - based on his reading of the Arabian Nights, classical mythology, and Georgian authors - were fortified and augmented throughout his life, providing him with a well-defined set of interrelated roles which he sometimes facetiously, sometimes tenaciously assumed: the Anglophile gentleman who upheld the most staid conventionality and lamented the "tragic rebellion of 1775-83," the Nordic warrior who reveled in dreams of adventure and blood, the proud citizen of the Roman Empire, the anemic decadent immersed in every form of human and metaphysical abnormality, the frigid scientist seeking truth by the strictest criteria of logic, the generous and brilliantly humorous friend, the xenophobic admirer of Mein Kampf who evolved into a quasi-socialist supporter of Franklin Roosevelt's New Deal, and the "cosmic-minded" dreamer of imaginary spheres that transcend the brief and aimless episode of human history. The last-named quality of cosmic-mindedness was perhaps less a discrete component of Lovecraft's temperament than the relatively stable foundation upon which his numerous personae were constructed. Philosophically, Lovecraft was a strict scientific materialist who held that the universe is a mechanical assemblage of forces wherein all values are simply fabrications having no validity outside the context of human imagination and that humanity itself is merely an evanescent phenomenon without any special dimension of soul or spirit to distinguish it from other forms of animate or inanimate matter. At the same time Lovecraft wrote that his strongest feelings were connected with a sense of unknown realms outside human experience, an irrationally perceived mystery and meaning beyond the world of crude appearances. It is particularly this tension between Lovecraft's sterile scientism and mystic imagination - whose contradictory relationship he always recognized and relished - that critics find is the source of the highly original character of his work.

Lovecraft's stories are commonly divided into three types: those influenced by the Irish fantasist Lord Dunsany, a diverse group of horror narratives set in New England, and tales sharing a background of cosmic legendry usually referred to as the "Cthulhu Mythos," a term coined by August Derleth and never used by Lovecraft himself. The Dunsanian stories begin with "Polaris," which Lovecraft actually wrote the year before his first reading of Dunsany's works. Nevertheless, his discovery of Dunsany was a crucial impetus to continue developing narratives more or less related to a tradition of fairy tales and typified by wholly imaginary settings and characters with otherworldly names. Stories in this vein are "The White Ship," "The Doom That Came to Sarnath," "The Cats of Ulthar," and The Dream-Quest of Unknown Kadath. Contrasting with these dreamlike romances are tales in which the central element of supernatural horror originates and is circumscribed in a realistic New England setting. Throughout his life Lovecraft was captivated by the architecture, landscape, and traditions of New England. In a letter of 1927, he wrote: "Sometimes I stumble accidentally on rare combinations of slope, curved street-line, roofs & gables & chimneys, & accessory details of verdure & background, which in the magic of late afternoon assume a mystic majesty & exotic significance beyond the power of words to describe. …All that I live for is to capture some fragment of this hidden & unreachable beauty; this beauty which is all of dream, yet which I feel I have known closely & revelled in through long aeons before my birth or the birth of this or any other world." To some extent, the fantasy realms of the Dunsanian stories are transfigurations of this New England of ideal beauty. On the other hand, Lovecraft simultaneously perceived and devoted much of his work to depicting a different side of his native region: the degeneracy and superstition that flourish in isolated locales, as described in "The Picture in the House" and "The Unnameable;" the survival of unearthly rites practiced in a quaint, colonial town in "The Festival;" the clan of ghouls that inhabits modern Boston in "Pickman's Model;" the horror interred beneath "The Shunned House," which was inspired by an actual home in the district of Providence where Lovecraft resided; and the foul aspirations of an eighteenth-century wizard which are recapitulated in twentieth-century Providence in The Case of Charles Dexter Ward. In other stories, those of the Cthulhu Mythos, Lovecraft provided literary travelogues to a New England that departed even further from the sites of his antiquarian wanderings, revising the geography so familiar to him to create the fictional world of Arkham, Innsmouth, and Dunwich. As he wrote to one of his correspondents: "Yes - my New England is a dream New England - the familiar scene with certain lights and shadows heightened (or meant to be heightened) just enough to merge it with things beyond the world." Among these "things" are the primeval and extrastellar pantheon of a body of myth that, although irregular in its details, is highly consistent as Lovecraft's expression of humanity's insignificant and unsteady place in the universe.

One of the most important and controversial issues in Lovecraft criticism is that regarding nomenclature for his Mythos stories. Various labels have been employed, from the broad designations of "horror" and "Gothic" to more discriminating terms such as "supernormal" and "mechanistic supernatural." At the source of this diverse terminology is the fact that, while these works clearly belong to the tradition of Gothic literature, Lovecraft did not make them dependent on the common mythic conceits associated with this tradition - such as ghosts, vampires, witches, werewolves, and other figures of folklore - and even when they do appear in his work, these entities are often modified to function against a new mythical background, one whose symbolism emphasizes the philosophical over the psychological. For example, Keziah Mason in "Dreams in the Witch-House" has all the appearance and appurtenances of a seventeenth-century New England witch; but instead of serving the demonic forces of Christian mythology, she is in league with extraplanetary forces wholly alien to the human sphere and ultimately beyond good or evil, superterrestrial entities blind to either the welfare or harm of the human species. This order of alien existence and its imposing relationship to human life is similarly displayed in such works as "The Call of Cthulhu," "The Dunwich Horror," "The Whisperer in Darkness," and "The Shadow over Innsmouth," while At the Mountains of Madness and "The Shadow out of Time" offer more elaborate development of cosmic civilizations whose nonhuman nature violates all earthly conceptions of reality, forcing upon the protagonists of these narratives an esoteric knowledge which they can neither live with nor disregard. The question of how to describe tales whose effect derives from the violation of the laws of nature rather than those of personal or public morality was somewhat resolved by Lovecraft himself when he applied the term "weird" to such works. In a letter of 1926, he wrote: "As to what is meant by 'weird' - and of course weirdness is by no means confined to horror - I should say that the real criterion is a strong impression of the suspension of natural laws or the presence of unseen worlds or forces close at hand." The literary consequences of this distinction between weirdness and horror may be noted in the remarks of critics who find horrific effects minimal in Lovecraft's stories, their power relying more on an expansive and devastating confrontation with the unknown.

Critical reaction to Lovecraft's work displays an unusual diversity, from exasperated attacks upon what are judged to be the puerile ravings of an artistic and intellectual incompetent to celebrations of Lovecraft as one of the greatest writers and thinkers of the modern era. His severest detractors regard him as an isolated neurotic, and even something of an imbecile, whose writings merely betray a pathetic estrangement from the concerns of adult society. For the most part admitting Lovecraft's eccentricity, his defenders find in his fiction, and more obviously in the five volumes of his Selected Letters, a complex vision of reality which could only be formed by a mind of exceptional independence. Summarizing his perception of existence and the implications this had for the outward aspect of his life, Lovecraft explained: "I preach & practice an extreme conservatism in art forms, society, & politics, as the only means of averting the ennui, despair, & confusion of a guideless & standardless struggle with unveiled chaos." While this reaction has been called pathological, and its manifestation as literature uninteresting for readers whose psychic functions remain sound, it has also inspired empathy, even admiration, as an existential ploy not without relevance for a world in which "chaos" has become a key word. With regard to the literary consequences of Lovecraft's character, a great deal of controversy has persisted over his prose style which, reflecting the division between his reactionary code and his sense of universal discord, varies from a highly formal, essay-like discourse to manic outbursts wherein rationality is sacrificed for poetic effect. Briefly, Lovecraft's prose has been derided as labored and archaic by critics who regard plain-spoken realism as the modern standard for fiction; at the same time, it has been praised by those who perceive its calculated suitability for the idiosyncratic nature of Lovecraft's fictional universe, which demands artificiality and a remoteness from the familiar as paradoxical requisites for a vivification of the unreal and the impossible.

The debate concerning the value of Lovecraft's work is, of course, hardly unique in the history of literature. Lovecraft himself was the first to argue both sides of this controversy, which often extends beyond his own work and calls into question the validity of all weird literature. As he described his position to one correspondent: "Doubtless I am the sort of shock-purveyor condemned by critics of the urbane tradition as decadent or culturally immature; but I can't resist the fascination of the outside's mythical shadowland, & I really have a fairly respectable line of literary predecessors to back me up." Elsewhere Lovecraft defended the weird tradition when he noted shared traits in his fiction and that of his contemporaries, contending that this similarity "illustrates the essential parallelism of the fantastic imagination in different individuals - a circumstance strongly arguing the existence of a natural & definite (though rare) mental world of the weird with a common background & fixed laws, out of which there must necessarily spring a literature as authentic in its way as the realistic literature which springs from mundane experience." For most of those concerned with this "world of the weird," Lovecraft has long taken his place among its most dedicated explorers and supreme documentarians.