When either good or evil is uncertain, it gives rise to FEAR or HOPE, according to the degrees of uncertainty on the one side or the other.
 David Hume, A Treatise of Human Nature (1738). copy citation

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Author David Hume
Source A Treatise of Human Nature
Topic uncertainty evil
Date 1738
Language English
Reference
Note
Weblink http://www.gutenberg.org/files/4705/4705-h/4705-h.htm

Context

“and the pleasure, which attends that passion, returns back to the direct affections, and gives new force to our desire or volition, joy or hope. When good is certain or probable, it produces joy. When evil is in the same situation there arises GRIEF or SORROW. When either good or evil is uncertain, it gives rise to FEAR or HOPE, according to the degrees of uncertainty on the one side or the other. DESIRE arises from good considered simply, and AVERSION is derived from evil. The WILL exerts itself, when either the good or the absence of the evil may be attained by any action of the mind or body.” source