The whole essence of good drawing - and of good thinking, perhaps - is to work a subject down to the simplest form possible and still have it believable for what it is meant to be.
“The economy of human time is the next advantage of machinery in manufactures.”
“We demand that people should be true to the pictures we have of them, no matter how repulsive those pictures may be: we prefer the true portrait in all its homogeneity, to one with a detail added which refuses to fit in.”