insanity, they admit them to be morbid and contend against them.
A question of deeper interest, and of closer relation to the subjects treated in this volume, is whether subjective visions are possible to the sane; and, if so, whether they are at all common, and liable to occur as isolated circumstances. On a full survey of the subject, both these questions must be answered in the affirmative. To say nothing of the visions produced by alcohol, opium, hashish, fever, blows upon the head, prolonged abstinence, deep anxiety, or those which precede attacks of epilepsy or of apoplexy, it is certain that hallucinations often arise without assignable cause or subsequent effect; and the subjects of them demonstrate their sanity by recognizing the unreal character of their perceptions.
Griesinger, one of the most eminent and discriminating writers on mental diseases, says: "Nothing would be more erroneous than to consider a man to be mentally diseased because he had hallucinations. The most extended experience shows rather that such phenomena occur in the lives of very distinguished and highly intellectual men, of the most different dispositions and various casts of mind, but especially in those of warm and powerful imagination." In illustration he speaks of Tasso, who, in the presence of Manco, carried on a long conversation with his protecting spirit; and of Goethe's well-known blue-gray vision, and his ideal flowers with their curious buds. He speaks briefly also of the hallucinations of Sir Walter Scott, Jean Paul, Benvenuto Cellini, Spinoza, Pascal; of Van Helmont, who saw his own soul in the form of a light with a human countenance; of Andral, the great physician, who experienced an hallucination of sight; and of Leuret, an investigator, thinker, and writer whose testimony may be implicitly trusted,
