"  so that we may unravel the web of memory and invention
    and discover how far and in what ways the crude
    material has been transformed. "

In short, a creative interest in a writer's creativity.

A great find, Rick.

From: Rickard Parker <[log in to unmask]>;
To: <[log in to unmask]>;
Subject: Re: How Eliot saw his letters.
Sent: Tue, Jun 26, 2012 1:33:03 PM

Not about letters but related.  Here is Eliot in his preface to
Stanislaus Joyce's biography of his brother, "My Brother´s
Keeper: James Joyce´s Early Years":

      Curiosity about the private life of a public man may
    be of three kinds: the useful, the harmless, and the
    impertinent. It is useful, when the subject is a
    statesman, if the study of his private life contributes
    to the understanding of his public actions; it is
    useful, when the subject is a man of letters, if the
    study throws light upon his published works. The line
    between curiosity which is legitimate and that which is
    merely harmless and that which is vulgarly impertinent,
    can never be precisely drawn. In the case of a writer,
    the usefulness of biographical information, for
    increasing and making possible a keener enjoyment or a
    more critical valuation, will vary according to the
    type of which the writer is representative, and the way
    in which he has exploited his own experience in his
    books. It is difficult to believe that greater
    knowledge about the private life of Shakespeare could
    much modify our judgment or enhance our enjoyment of
    his plays; no theory about the origin or mode of
    composition of the Homeric poems could alter our
    appreciation of them as poetry. With a writer like
    Goethe, on the other hand, our interest in the man is
    inseparable from our interest in the work; and we are
    impelled to supplement and correct what he tells us in
    various ways about himself, with information from
    outside sources; the more we know about the man, the
    better, we think, we may come to understand his poetry
    and his prose.

      In the case of James Joyce we have a series of
    books, two of which at least as so autobiographical
    in appearance that further study of the man and his
    background seems not only suggested by our own
    inquisitiveness, but almost expected by the author
    himself. We want to know who are the originals of his
    characters, and what were the origins of his episodes,
    so that we may unravel the web of memory and invention
    and discover how far and in what ways the crude
    material has been transformed. Our interest extends,
    therefore, inevitably and justifiably, to Joyce’s
    family, to his friends, to every detail of the
    topography and life of Dublin, the Dublin of his
    childhood, adolescence and young manhood.

    Rick Parker