This triviality made him think of collecting many such moments together in a book of epiphanies.  By epiphany—a sudden spiritual manifestation, whether in the vulgarity of speech or gesture, or in a memorable phrase of the mind itself.  He believed that it was for the man of letters to record these epiphanies with extreme care, seeing that they themselves are the most delicate and evanescent of moments.

What It Means

This is a placeholder explanation generated by the low-overhead model. It interprets "This triviality made him think of collecting many such moments together in a book of epiphanies.  By epiphany—a sudden spiritual manifestation, whether in the vulgarity of speech or gesture, or in a memorable phrase of the mind itself.  He believed that it was for the man of letters to record these epiphanies with extreme care, seeing that they themselves are the most delicate and evanescent of moments." in the context of "James Joyce, A Portrait of the Artist as a Young Man (1916)." to mean that wisdom is timeless.