Likes (and dislikes)

I've long been fascinated by one author's  unfathomable passion for another. It's the unfathomability that counts: obvious or often-written-about cases (James's admiration for Flaubert or Pope's for Horace for instance) may be important historically but usually aren't fascinating of themselves. (Except sometimes: why did Wordsworth's poems hit the young de Quincey (and Hazlitt too for that matter) with such overwhelming force?  There's a story still to be told there...).
And it doesn't matter much whether the writers in question are obscure or famous.  Why was John Byrom so admiring of Malebranche?  It's an intriguing question, even though these days nobody knows whom John Byrom was. Could the answer be that Malebranche reconfigures the concept of taste in ways which prefigure Le Bos and other later commentators? Probably not. Could it be that he prefigure the Rousseuvian general will? More likely: since that makes sense for Toryism. But it's clearly an insufficient reason.
Some other examples: What exactly did Simone Weil see in Lawrence of Arabia?  Jocelyn Brooke in Aldous Huxley?  Or, another famous case, why exactly did the young T.S. Eliot so admire John Donne?  And, come to that, why did George Eliot and James both hate Stendhal so much?  Why did Forster dismiss James?

It seems to me that answers to such questions would help us understand the force fields which order literary history, i.e. the emotional and ethical dispositions that shape the dispersion of literary styles and tropes across time.