A favorite Proust quote of mine: Moncrieff translation, Vol II, p. 1001-2
For instinct dictates the duty to be done and intelligence supplies the excuses for evading it. But in art excuses count for nothing; good intentions are of no avail; the artist must at every instant heed his instinct; so that art is the most real of all things, the sternest school in life and truly the Last Judgment. This book, the most difficult of all to decipher, is also the only one dictated to us by reality, the only one the ‘imprinting’ of which on our consciousness was done by reality itself.
No matter what idea life may have implanted with us, its material representation, the outline of the impression it has made upon us, is always the guarantee of its indispensable truth. The ideas formed by pure intellect have only a logical truth, a potential truth; the selection of them is an arbitrary act. The book written in symbolic characters not traced by us is our only book. Not that the ideas we form ourselves may not be logically correct, but we do not know whether they are true.
Only the subjective impression, however inferior the material may seem to be and however improbable the outline, is a criterion of truth, and for that reason it alone merits being apprehended by the mind, for it alone is able, if the mind can extract this truth, to lead the mind to a greater perfection and impart to it a pure joy. The subjective impression is for the writer what experimentation is for the scientist, but with the difference, that with the scientist the work of the intelligence precedes and with the writer it comes afterwards.
Anything we have not had to decipher and clarify by our own personal effort, anything that was clear before we intervened, is not our own. Nothing comes from ourselves but that which we draw out of the obscurity within us and which is unknown to others. And since art is a faithful recomposing of life, around these truths that one has attained within oneself there floats an atmosphere of poetry, the sweetness of a mystery, which is merely the semi-darkness through which we have come.