Dear NT:

You wrote:
> The following is a slightly modified sentence from a book. It is about what the comparison between the lectures (spoken word) and the published texts of a particular writer shows regarding his work. I have a problem with the phrase: “for all that it enriches…”.
>
> “Such a comparison (between “unscripted” lectures and texts that were later derived from these lectures and published) shows how the repeated revisions he undertook on the road to publication, for all that they enrich the intellectual content and precision of a work, can sometimes have a sobering effect on the extempore spoken word; or conversely, it shows how a long underlying text can acquire new life and directness when used as a source for a lecture not read from a prepared script.”
>
> What does “for all that” mean here?
>
This is something of an idiom. The most famous example is the poem by Robert Burns, “A Man’s a Man for All That.” In the sentence you gave “all” is an indefinite pronoun, not an adjective. “They” clearly refers to the “revisions,” so the sentence is saying “for all that the revisions…” Substitute “everything” or “all things” for “all” and that may help you
understand the meaning.