To shew yet farther, the influence of the passions on the animal economy, let us consider the different constitutions of men. Those who have very springy, lively and elastic fibres, have the quickest of sensations, a weaker impulse providing a stronger sensation in them. They generally excel in the animal faculty of imagination. Hence the poet,
--Genius irritable vatum.
Poets are soon provok'd.
And therefore, your men of imagination are generally given to sensual pleasure, because the objects of sense yield them a more delicate touch, and a livelier sensation, than they do others. But if they happen to live so long (which is hardly possible), in the decline of life they pay dearly for the youthful days of their vanity. Those rigid, stiff and unyielding fibres, have less warm sensations, because it requires a greater resistance. Those excel most in the labours of the understanding, or the intellectual faculties, retain their impressions longest, and pursue the farthest; and are most susceptible of the slow and lasting passions, which secretly consume them as chronic diseases do. And lastly, those whose organs of sensation are (if I may speak so) unelastic, or entirely callous, resty for want of exercise, or any way obstructed, or naturally ill-formed, as they have scarce any passions at all, or any lively sensations, and are incapable of lasting impressions; so they enjoy the firmest heath, and are subject to the fewest diseases: such are ideots, peasants, and mechanics, and those we call indolent people.
Cheyne's description of natural variation in feeling is interesting for several reasons. The limited catalogue of sensation he provides only allows for three physical types of feeling: the sensitive, the cool, and the dead. The first two types point towards different types of intellectual: the poet and the philosopher. In this case, sensibility becomes tied to one's capacity for thought; the ability to feel indicates the sort of work one might produce. The picture of the super-sensitive artist reminds one of, among others, Richardson the hypochondriac, and Sterne the consumptive. One also thinks of Belton's death in Clarissa; the libertine on his death bed, paying dearly in physical and spiritual torment "for the youthful days of his vanity." Then there is the philosopher on slow boil, going mad at the same rate at which he approaches complex scientific and moral problems. Finally, Cheyne shifts out of the artistic and intellectual to discuss feeling in totally classist terms; the ruddy vitality of the mechanic is compromised by his total inability to feel. It is, I think, noteworthy how smoothly Cheyne connects the terms "ideot" and "peasant."