Reading Flaubert's correspondence

Lately I've been reading Flaubert's correspondence with Turgenev, and with George Sand.
The letters with Turgenev do say something about Flaubert's personality, life and aesthetic views, and explain the close friendship between these 2 writers. They have the same views on life, literature and politics, the same pessimism and melancholy, the same disbelief in the possibility of happiness, the same principle of an impersonal style (of withholding comments and keeping their personal beliefs out of their novels), the same focus on style and details, the same attitude towards politics (follow what's going on, without belonging to a party or a group) and the same refusal to have any system. They have the same admiration, with reservations, for Tolstoy, for instance. And when Flaubert's attacked on various sides for Sentimental Education, Turgenev's 1 of the few who see its worth.
At the same time these letters show some differences between the 2. Flaubert's "the hermit of Croisset", with a small circle of friends, whereas Turgenev's the man of society, so Flaubert's more emotionally dependent and sometimes even sulky like a child. He's also more pessimistic- he has a gloomy view on everything, seeing life as futile and people as stupid, but Turgenev consoles him that it's more like a symptom of old age.
However, the Flaubert- George Sand letters are fascinating, because they're exchanges of ideas and feelings between 2 very different persons. They discuss, they debate, they give each other advice besides affection and consolation, they explain themselves and try to convince each other. As Virginia Woolf puts it, "She brings out all his peculiar qualities so finely that no autobiography could tell so much as he tells almost unconsciously". For most of the time reading the correspondence, I've felt more drawn to George Sand, for her love of life and acceptance of everything in spite of the negative bits. Flaubert's pessimism and disdain, bordering on cynicism and misanthropy, can be frustrating, his scorn for the mass and his disbelief in democracy and universal suffrage can be frustrating, and his ceaseless lamentations over the labour of writing can get on one's nerves. George Sand apparently feels the same about his attitudes. I can't help feeling, as I think of Tolstoy, that perhaps this pessimism makes Flaubert limited in some ways, and inferior to Tolstoy. 
As I read on, I have better understanding of his negativity. He sees through pretensions and notices all the stupidity around him. He refuses to rise above human folly and the silliness of others, as he says George Sand does, but stares at everything, reads everything, avoids nothing- the more he reads about history and science and numerous books, the more convinced he is of the barbarism and stupidity of people that will not change- he takes in everything and lets it all engulf him so that he sinks into sadness and melancholy. Understanding his view on the mass, I can also understand why he's against universal suffrage and democracy- of course he's mistaken, but I have hindsight, I know how democracy has turned out in spite of the early scepticism, and more importantly, unlike a lot of people, I have known both dictatorship and democracy, and Flaubert doesn't (not that I have any illusion about democracy- it's not without faults, but it's the best thing we've ever had). I read the letters and see Flaubert as a character on the pages, and seeing him in context, in his place and time, can sympathise with his views and see why he has such thoughts. These letters shed some light on Madame Bovary and Sentimental Education. 
Fascinating stuff.