WHAT RULES SHOULD BE GIVEN TO BOYS LEARNING TO PAINT.

We know for certain that sight is one of the most rapid actions we
can perform. In an instant we see an infinite number of forms, still
we only take in thoroughly one object at a time. Supposing that you,
Reader, were to glance rapidly at the whole of this written page,
you would instantly perceive that it was covered with various
letters; but you could not, in the time, recognise what the letters
were, nor what they were meant to tell. Hence you would need to see
them word by word, line by line to be able to understand the
letters. Again, if you wish to go to the top of a building you must
go up step by step; otherwise it will be impossible that you should
reach the top. Thus I say to you, whom nature prompts to pursue this
art, if you wish to have a sound knowledge of the forms of objects
begin with the details of them, and do not go on to the second
[step] till you have the first well fixed in memory and in practice.
And if you do otherwise you will throw away your time, or certainly
greatly prolong your studies. And remember to acquire diligence
rather than rapidity.