TANZI'S DEFINITION OF HALLUCINATIONS AND ILLUSIONS

In 1905 the Italian psychiatrist Eugenio Tanzi (1856-1934) defined hallucinations and *illusions as follows. "By an hallucination is meant the occurrence of internal images, which, on account of their remarkable vividness, are referred externally as if they had come from without, and which are mistaken for an objective reality. By illusion is meant the involuntary process by which imaginary attributes are added to an existing object, under the conviction that they are real, or, at least, with the feeling that they may be so."

Tanzi, E. (1909).A text-book of mental diseases. Translated by Ford Robertson, W., Mackenzie, T.C. London: Rebman Limited.