1890. Mercier was both a psychologist and a medical doctor. He regarded psychology as the science of mental phenomena, rather than the science of individual human behavior. Contents: The Nervous System; The Mind; What Insanity Is; The Causes of Insanity-The First Law of Heredity; The Causes of Insanity-The Second Law of Heredity; The Causes of Insanity-Direct Stress; The Causes of Insanity-Indirect Stress of Internal Origin; The Causes of Insanity-Indirect Stress of External Organ; The Forms of Insanity-Idiocy and Imbecility; The Forms of Insanity-Sleep, Old Age, and Drunkenness; The Forms of Insanity-Melancholia; The Forms of Insanity-Exaltation; and The Forms of Insanity-Dementia. See other titles by this author available from Kessinger Publishing.