That's Tolstoy pictured above. I was thumbing through his "What is Art?" today and I was reminded all over again of what a terrific thinker the man was. I don't always agree but it doesn't matter. The best best writers are worth reading whether you agree or not.
The word "infected" is important. It keeps coming up again and again. A great work of art infects its audience like a benign disease. They're mostly incapable of resisting the infection and they'll likely spread it to others. That's how art contributes to the spread of great ideas.
Some people through malice or stupidity are resistent to artistic infection and Tolstoy has no use for them. For Tolstoy critics fall into this category. I like critics myself. They're often wrong but they get useful arguments started and stimulate the market for art.
I wonder what Tolstoy would make of the picture of the grimacing boy above. My guess is that he'd hate it. He believed that in order to infect, a work of art has to be capable of infecting. In other words, it must contain an experience that people will welcome or that touches them deeply.
Dickens also put a lot of stock in sincerity. The editor who wrote the preface thought this was ridiculous since, if you take it literally, it means that an actor who plays a killer must really want to kill the other actors. Maybe Tolstoy did take it to this extreme but the idea is still useful on some level.
Tolstoy was a Christian and he believed that Christian themes are uniquely appealing because they deal with the universal brotherhood of man and exclude nobody. He said art can inadvertantly become exclusionary, appealing only to aristocrats or to people we'd call "hip" today. Amazingly he said Beethoven's Ninth was like that. It was something for the art crowd.
Examples of art he approved of were Dickens "Christmas Carol" and "David Copperfield" and Hugo's "Les Miserables."
Sincerity and earnestness is precicely what a lot of modern media lacks. It's a measure of the greatness of some writers that they dare to voice great truths even though the truths are intuitive and are often difficult to express with words.