Millet was one of those artists on whom a few formal ideas make so deep an impression that they feel compelled to spend the whole of their lives in trying to lever them out. Perhaps this is the chief distinguishing mark of the classical artist; certainly it is what distinguishes his use of subject matter from that of the illustrator. The illustrator is essentially a reporter, his subjects come from the outside, lit by a flash. A subject comes to the classical artist from inside, and when he discovers confirmation of it in the outside world he feels that it has been there all the time. He must give to his subjects an air of complete inevitability, and this becomes a problem of formal completeness. That is why the classic artists, Degas no less than Poussin, return to the same motives again and again, hoping each time to mould the subject closer to the idea.