Date: 1464

"For Simple Being, which is visible to the mind alone, is to the mind as the being of color is to the sense of sight."

— Nicholas of Cusa (1401-1464)

Date: 1464

" [I]f someone were to turn his mind's sight to the possibility, or power, of oneness: he surely would see in every number and in all plurality only oneness's power"

— Nicholas of Cusa (1401-1464)

Date: 1464

"Therefore, my dearly beloved Peter, with keen directedness turn your mind's eye to this secret, and with this analysis enter into my writings and into whatever other writings you read, and occupy yourself especially with my books and sermons."

— Nicholas of Cusa (1401-1464)

Date: 1785

"One cannot give too many or too frequent warnings against this laxity, or even mean cast of mind, which seeks its principle among empirical motives and laws; for,human reason in its weariness gladly rests on this pillow and in a dream of sweet illusions (which allow it to embrace a cloud instead...

— Kant, Immanuel (1724-1804)

Date: 1807

"The individual whose substance is the more advanced Spirit runs through this past just as one who takes up a higher science goes through the preparatory studies he has long since absorbed, in order to bring their content to mind: he recalls them to the inward eye, but has no lasting interest in ...

— Hegel, G. W. F. (1770-1831)

Date: 1805-6, published 1833-6

"Kant however places the matter somewhat in this fashion: there are things-in-themselves outside, but devoid of time and space; consciousness now comes, and it has time and space beforehand present in it as the possibility of experience, just as in order to eat it has mouth and teeth, &c., as con...

— Hegel, G. W. F. (1770-1831)

Date: 1805-6, published 1833-6

"Knowledge itself is in fact the unity and truth of both moments; but with Kant the thinking understanding and sensuousness are both something particular, and they are only united in an external, superficial way, just as a piece of wood and a leg might be bound together by a cord."

— Hegel, G. W. F. (1770-1831)

Date: December 1840

"Perhaps a friendly Morgan le Fay will make Siegfried's castle rise again for me or show my mind's eye what heroic deeds are reserved for his sons of the nineteenth century."

— Engels, Friedrich (1820-1895)

Date: 1851

"And so it happens that the person who reads a great deal—that is to say, almost the whole day, and recreates himself by spending the intervals in thoughtless diversion, gradually loses the ability to think for himself; just as a man who is always riding at last forgets how to walk."

— Schopenhauer, Arthur (1788-1860)

Date: 1851

"For to read in every spare moment, and to read constantly, is more paralysing to the mind than constant manual work, which, at any rate, allows one to follow one’s own thoughts."

— Schopenhauer, Arthur (1788-1860)