"The mind, therefore, in producing the vital and other involuntary motions, does not act as a rational, but as a sentient principle; which, without reasoning upon the matter, is as necessarily determined by an ungrateful sensation or stimulus affecting the organs, to exert its power, in bringing about these motions, as is a balance, while, from mechanical laws, it preponderates to that side where the greatest weight prevails."
— Whytt, Robert (1714-1766)
(Sect XI, p. 289)
Robert Whytt, An Essay on the Vital and Other Involuntary Motions of Animals (Edinburgh: Printed by Hamilton, Balfour, and Neill, 1751). <Link to Google Books>