Inspiration

Inspiration, an earnest, divinely-awakened, soul-subduing sense and perception of the presence of the invisible in the visible, of the infinite in the finite, of the ideal in the real, of the divine in the human, and, in ecstatic moments, of very God in man, accompanied with a burning desire to impart to others the vision revealed; distinguished as “seraphic” from insanity as “demonic” by this, that the inspired man sees an invisible which is there, and the insane an invisible which is not there, states of mind so like otherwise that the one may be, and often is, mistaken for the other, the inspired man taken for an insane, and the insane man for an inspired.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)