Leonardo DaVinci

The mind of the painter must resemble a mirror, which always takes the colour of the object it reflects and is completely occupied by the images of as many objects as are in front of it. Therefore you must know, O Painter! that you cannot be a good one if you are not the universal master of representing by your art every kind of form produced by nature. And this you will not know how to do if you do not see them, and retain them in your mind. Hence as you go through the fields, turn your attention to various objects, and, in turn look now at this thing and now at that, collecting a store of diverse facts selected and chosen from those of less value. But do not do like some painters who, when they are wearied with exercising their fancy dismiss their work from their thoughts and take exercise in walking for relaxation, but still keep fatigue in their mind which, though they see various objects around them, do not apprehend them; but, even when they meet friends or relations and are saluted by them, although they see and hear them, take no more cognisance of them than if they had met so much empty air.

When you have well learnt perspective and have by heart the parts and forms of objects, you must go about, and constantly, as you go, observe, note and consider the circumstances and behaviour of men in talking, quarrelling or laughing or fighting together – the action of the men themselves and the actions of the bystanders, who separate them or who look on. And take a note of them with slight strokes, in a little book which you should always carry with you. And it should be of tinted paper, that it may not be rubbed out, but change the old when full for a new one; since these things should not be rubbed out but preserved with great care; for the forms, and positions of objects are so infinite that the memory is incapable of retaining them, wherefore keep these sketches as your guides and masters.

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Man when flying must stand free from the waist upwards so as to be able to balance himself as he does in a boat so that the centre of gravity in himself and in the machine may counter-balance each other, and be shifted as necessity demands for the changes of its centre of resistance.

The youth should first learn perspective, then the proportions of objects. Then he may copy from some good master, to accustom himself to fine forms. Then from nature, to confirm by practice the rules he has learnt. Then see for a time the works of various masters. Then get the habit of putting his art into practice and work.

And if you are not conscious of this in yourself study it in others and profit by their faults

declaimers of the works of others, must be regarded and not otherwise esteemed than as the object in front of a mirror, when compared with its image seen in the mirror. For the first is something in itself, and the other nothingness – folks little indebted to Nature, since it is only by chance that they wear the human form and without it I might class them with the herds of beasts.

The sorest misfortune is when your views are in advance of your work

‘I will go my own way and withdraw apart, the better to study the forms of natural objects,’ I tell you, you will not be able to help often listening to their chatter. And so, since one cannot serve two masters, you will badly fill the part of a companion, and carry out your studies of art even worse. And if you say: ‘I will withdraw so far that their words cannot reach me and they cannot disturb me,’ I can tell you that you will be thought mad. But, you see, you will at any rate be alone. And if you must have companionship find it in your studio. This may assist you to have the advantages which arise from various speculations. All other company may be highly mischievous.

Nature teaches us that an object can never be seen perfectly unless the space between it and the eye is equal, at least, to the length of the face.

all equally large and equally distant, that which is most brightly illuminated will appear to the eye nearest and largest.