the mechanical practice of painting is learned in some measure by it, let
those choice parts only be selected which have recommended the work to
notice. If its excellence consists in its general effect, it would be
proper to make slight sketches of the machinery and general management of
the picture. Those sketches should be kept always by you for the
regulation of your style. Instead of copying the touches of those great
masters, copy only their conceptions. Instead of treading in their
footsteps, endeavour only to keep the same road. Labour to invent on
their general principles and way of thinking. Possess yourself with
their spirit. Consider with yourself how a Michael Angelo or a Raffaelle
would have treated this subject: and work yourself into a belief that
your picture is to be seen and criticised by them when completed. Even
an attempt of this kind will rouse your powers.

But as mere enthusiasm will carry you but a little way, let me recommend
a practice that may be equivalent, and will perhaps more efficaciously
contribute to your advancement, than even the verbal corrections of those
masters themselves, could they be obtained. What I would propose is,
that you should enter into a kind of competition, by painting a similar
subject, and making a companion to any picture that you consider as a
model. After you have finished your work, place it near the model, and
compare them carefully together. You will then not only see, but feel
your own deficiencies more sensibly than by precepts, or any other means
of instruction. The true principles of painting will mingle with your
thoughts. Ideas thus fixed by sensible objects, will be certain and
definitive; and sinking deep into the mind, will not only be more just,
but more lasting than those presented to you by precepts only: which
will, always be fleeting, variable, and undetermined.

This method of comparing your own efforts with those of some great