... was the original name of this blog and the subject of the first post on it, so I'm always delighted to find something bloggable that can take the "marginalia" tag.
I love this one, from the biography "John Adams" (pp. 763-764)(commission earned):
Unlike [Thomas] Jefferson, who seldom ever marked a book, and then only faintly in pencil, [John] Adams, pen in hand, loved to add his comments in the margins. It was part of the joy of reading for him, to have something to say himself, to talk back to, agree or take issue with, Rousseau, Condorcet, Turgot, Mary Wollstonecraft, Adam Smith, or Joseph Priestley.
Ah, John Adams was a proto-blogger!