Assertion: evil | /r/HasProperty | imperceptible
Facets:
value: without each other
type: OTHER
Source sentences:
text: Perceptions are based on contrast, so that light and dark, good and evil, are imperceptible without each other; in this context, these sets of opposites show a certain symmetry, but a basic study of optics teaches us that light has a physical presence of its own, whereas darkness does not: no "anti-lamp" or "flashdark" can be constructed which casts a beam of darkness onto a surface that is otherwise well-lit.