The "Life of Milton," by Prof. Masson, is a difficulty for the critics. It is very laborious, very learned, and in the main, we believe, very accurate; it is exceedingly long,--there are 780 pages in this volume, and there are to be two volumes more; it touches on very many subjects, and each of these has been investigated to the very best of the author's ability. No one can wish to speak with censure of a book on which so much genuine labor has been expended; and yet we are bound, as true critics, to say that we think it has been composed upon a principle that is utterly erroneous. In justice to ourselves we must explain our meaning. There are two methods on which biography may consistently be written. The first of these is what we may call the "exhaustive" method. Every fact which is known about the hero may be told us; everything which he did, everything which he would not do, everything which other people did to him, everything which other people would not do to him, may be narrated at full length. We may have a complete picture of all the events of his life; of all which he underwent, and all which he achieved. We may, as Mr. Carlyle expresses it, have a complete account "of his effect upon the universe, and of the effect of the universe upon him." [2] We admit that biographies of this species would be very long, and generally very tedious; we know that the world could not contain very many of them: but nevertheless, the principle on which they may be written is intelligible.