"For one obscure or confused Idea, especially if it be of great Importance in the Question, intermingled with many clear ones, and placed in its Variety of Aspects towards them, will be in Danger of spreading Confusion over the whole Scene of Ideas, and thus may have an unhappy Influence to overwhelm the Understanding with Darkness, and pervert the Judgment. A little black Paint will shamefully tincture and spoil twenty gay Colours."
— Watts, Isaac (1674-1748)
Most text drawn from Google Books. See The Improvement of the Mind: or, a Supplement to the Art of Logick: Containing a Variety of Remarks and Rules for the Attainment and Communication of Useful Knowledge, in Religion, in the Sciences, and in Common Life. By I. Watts, D.D. (London: Printed for James Brackstone, at the Globe in Cornhill, 1741). <Link to ESTC><Link to 2nd edition in Google Books>