Date: 1778

"So steht unser Körper zwischen Seele und der übrigen Welt in der Mitte, Spiegel der Wirkungen von beiden. [Thus our body stands between soul and ambient world, in the middle, mirror of the effect of both.]"

— Lichtenberg, Georg Christoph (1742-1799)

Date: 1818, 1859

"Now this is by no means possible, for as soon as we turn into ourselves to make the attempt, and seek for once to know ourselves fully by means of introspective reflection, we are lost in a bottomless void; we find ourselves like the hollow glass globe, from out of which a voice speaks whose cau...

— Schopenhauer, Arthur (1788-1860)

Date: 1878

"All religion, however, is nothing but the fantastic reflection in men's minds of those external forces which control their daily life, a reflection in which the terrestrial forces assume the form of supernatural forces."

— Engels, Friedrich (1820-1895)