When "pyromania" from 1840-1890 is reviewed, it stands out as a concept that at first found favor in an era of moral insanity and moral treatment. During this period pyromania was variously labeled as a form of monomania, moral insanity, impulsive mania, or instinctive mania. As early as 1850, and clearly after the Civil War, however, controversial arguments regarding the locus of personal responsibilty emerged. Arguments were put forward that there could be diseased brains but not diseased minds. Without the proof of an organic lesion in the brain, fire-setting became an act whose locus rested in the individual's moral fabric, and in this historical context became a nonmedical concern punishable by law. Pyromania, at the hands of those physicians who limited insanity to disorders of the brain, might have received the same fate as other diseases of the mind or will: it could have simply been dismissed. But it lingered. The period 1880-1917 witnessed professional attention directed toward prophylaxis, mental hygiene, and a reorientation of American psychiatry toward an endorsement of psychotherapy (Sicherman, 1980). Attention to pyromania was more quiescent than it had been. The development of psychoanalytic theory which followed allowed for the re-emergence of pyromania as a disease entity. The diagnosis then flourished from 1924 until 1957, with descriptions of it including: an irresistible impulse, a urethra-erotic character trait, an obsession, or a psychosexually based impulse neurosis. The period of 1924-1985 can be viewed as a repetition of the period between 1840-1890 in terms of the evolution of the place of pyromania in the lexicon of psychiatry, of its existence as a disease entity, and of its implications for personal responsibility for destructive acts. Supported at the outset of this later period as a disease, this time grounded in psychoanalytic rather than moral theories of responsibility, it loses favor as the psychobiologic position ascends. And like the preceding period, the conception of pyromania as a specific disorder wanes but never dies, as advocacy for the psychodynamic (replacing moral) approach diminishes but does not disappear. The cyclical nature of pyromania has parallels in cycles of reform in standards of civil commitment (Livermore, Malmquist & Meehl, 1958; Dershowitz, 1974), in the use of physical therapies and medications (Tourney, 1967; Mora, 1974), in treatment of the chronically mentally ill (Deutsch, 1949; Morrissey & Goldman, 1984), and in institutional practices (Treffert, 1967; Morrissey, Goldman & Klerman (1980).(ABSTRACT TRUNCATED AT 400 WORDS)