The dangerous prevalence of imagination

‘Disorders of intellect, answered Imlac, happen much more often than superficial observers will easily believe. Perhaps, if we speak with rigorous exactness, no human mind is in its right state. There is no man whose imagination does not sometimes predominate over his reason, who can regulate his attention wholly by his will, and whose ideas will come and go at his command.* No man will be found in whose mind airy notions do not sometimes tyrannise, and force him to hope or fear beyond the limits of sober probability. All power of fancy over reason is a degree of insanity; but while this power is such as we can controul and repress, it is not visible to others, nor considered as any depravation of the mental faculties: it is not pronounced madness but when it comes ungovernable, and apparently influences speech or action.*