"In general we may remark, that the minds of men are mirrors to one another, not only because they reflect each others emotions, but also because those rays of passions, sentiments and opinions may be often reverberated, and may decay away by insensible degrees."
— Hume, David (1711-1776)
(II.ii.5, pp. 157-8)
David Hume, A Treatise of Human Nature. Being an Attempt to Introduce the Experimental Method of Reasoning into Moral Subjects. 3 vols. (London: Printed for John Noon, 1739; Thomas Longman, 1740). <Link to ESTC><Link to ECCO><Link to ECCO-TCP><Link to OLL>
Reading David Hume, A Treatise of Human Nature, eds. D. F. and M. J. Norton (Oxford: OUP, 2000). Searching in Past Masters and OLL editions.