The will can only become visible in the motives, as the eye only manifests its power of seeing in the light.
 Arthur Schopenhauer, The World as Will and Representation (1819). copy citation

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Author Arthur Schopenhauer
Source The World as Will and Representation
Topic power light
Date 1819
Language English
Reference
Note Translated by R. B. Haldane and J. Kemp
Weblink http://www.gutenberg.org/files/38427/38427-h/38427-h.html

Context

“Of what nature this example may be, what form the motive may have and impart to it, is not essential; the important point here is that something is willed in general and the degree of intensity with which it is so willed. The will can only become visible in the motives, as the eye only manifests its power of seeing in the light. [pg 422] The motive in general stands before the will in protean forms. It constantly promises complete satisfaction, the quenching of the thirst of will. But whenever it is attained it at once appears in another form, and thus influences the will anew, always according to the degree of the intensity of this will, and its relation to knowledge which are revealed as empirical character, in these very examples and instances.” source