People of genius have, very frequently, impaired their constitutions by study or careless inattention to their health, and the violence of their passions bearing a proportion to the vigour of their intellects, the sword's destroying the scabbard has become almost proverbial, and superficial observers have inferred from thence, that men of genius have commonly weak, or, to use a more fashionable phrase, delicate constitutions. Yet the contrary, I believe, will appear to be the fact; for, on diligent inquiry, I find that strength of mind has, in most cases, been accompanied by superior strength of body, -- natural soundness of constitution, -- not that robust tone of nerves and vigour of muscles, which arise from bodily labour, when the mind is quiescent, or only directs the hands.
Dr. Priestley has remarked, in the preface to his biographical chart, that the majority of great men have lived beyond forty-five. And, considering the thoughtless manner in which they have lavished their strength, when investigating a favourite science they have wasted the lamp of life, forgetful of the midnight hour; or, when, lost in poetic dreams, fancy has peopled the scene, and the soul has been disturbed, till it shook the constitution, by the passions that meditation had raised; whose objects, the baseless fabric of a vision, faded before the exhausted eye, they must have had iron frames. Shakspeare never grasped the airy dagger with a nerveless hand, nor did Milton tremble when he led Satan far from the confines of his dreary prison. -- These were not the ravings of imbecility, the sickly effusions of distempered brains; but the exuberance of fancy, that 'in a fine phrenzy' wandering, was not continually reminded of its material shackles.