
The Notebooks of Leonardo da Vinci (1883), II Linear Perspective
The Notebooks of Leonardo da Vinci (1883), I Prolegomena and General Introduction to the Book on Painting
Context: The eye — which sees all objects reversed — retains the images for some time. This conclusion is proved by the results; because, the eye having gazed at light retains some impression of it. After looking (at it) there remain in the eye images of intense brightness, that make any less brilliant spot seem dark until the eye has lost the last trace of the impression of the stronger light.
The Notebooks of Leonardo da Vinci (1883), II Linear Perspective
Balsamo the Magician (or The Memoirs of a Physician) by Alex. Dumas (1891)
“The eye of the intellect "sees in all objects what it brought with it the means of seeing."”
Varnhagen von Ense's Memoirs.
1820s, Critical and Miscellaneous Essays (1827–1855)
Address on The Method of Nature http://www.infomotions.com/alex2/authors/emerson-ralph/emerson-method-734/ (1841)
The Notebooks of Leonardo da Vinci (1883), II Linear Perspective
The Notebooks of Leonardo da Vinci (1883), I Prolegomena and General Introduction to the Book on Painting
1790s, Letter to Revd. Dr. Trusler (1799)
The Notebooks of Leonardo da Vinci (1883), II Linear Perspective
XI, 26, Parts of this passage has been heavily compared with later statements of René Descartes; in Latin and with a variant translations:
The City of God (early 400s)
Context: We both are, and know that we are, and delight in our being, and our knowledge of it. Moreover, in these three things no true-seeming illusion disturbs us; for we do not come into contact with these by some bodily sense, as we perceive the things outside of us of all which sensible objects it is the images resembling them, but not themselves which we perceive in the mind and hold in the memory, and which excite us to desire the objects. But, without any delusive representation of images or phantasms, I am most certain that I am, and that I know and delight in this. In respect of these truths, I am not at all afraid of the arguments of the Academicians, who say, What if you are deceived? For if I am deceived, I am. For he who is not, cannot be deceived; and if I am deceived, by this same token I am. And since I am if I am deceived, how am I deceived in believing that I am? for it is certain that I am if I am deceived. Since, therefore, I, the person deceived, should be, even if I were deceived, certainly I am not deceived in this knowledge that I am. And, consequently, neither am I deceived in knowing that I know. For, as I know that I am, so I know this also, that I know. And when I love these two things, I add to them a certain third thing, namely, my love, which is of equal moment. For neither am I deceived in this, that I love, since in those things which I love I am not deceived; though even if these were false, it would still be true that I loved false things. For how could I justly be blamed and prohibited from loving false things, if it were false that I loved them? But, since they are true and real, who doubts that when they are loved, the love of them is itself true and real? Further, as there is no one who does not wish to be happy, so there is no one who does not wish [themself] to be [into being]. For how can he be happy, if he is nothing?