As regards portraiture in general, the public may, without injury to Art or history, employ the painters who make the prettiest pictures of them; it doesn't matter to the future, if Mr. Jenkins, or even the Hon. Mr. Twaddle, has employed the promising Mr. Mahlstock to perpetuate him with a hundred transitory and borrowed graces,--if the talented young _littérateur_, Mr. Simeah, has been found by his limner to resemble Lord Byron amazingly, and has in consequence consented to sit for a half-length, to be done _à la Corsair_, etc., etc.; but for our men of thought, for those whose works will stand to all time as the signals pointing out the road a nation followed, whose presence and acts shall be our intellectual history,--it is of some little moment that these should be given to us in such visible form, that men shall not conjecture, a thousand years hence, if Emerson were really a man, or a name under which some metaphysical club chose to publish their philosophies. In psychological history, portraits are as necessary as dates; and one of the most valuable gifts to an age is a great portrait-painter,--a Titian, a Gainsborough, a Reynolds, or a Page,--which last has more of the Titianesque character than any one who has painted since the great Venetians lived, and few, indeed, are the generations so endowed. Beside this full insight and representation of character, which makes the ideal portraiture, we have the less complete, but only in degree less valuable, apprehension which results from a point of sympathy, a likeness of liking in one or more fields of thought, a common sensitiveness, a common interest; and the rarer sympathy between artist and subject, of that intimacy and complete understanding of personal character, which, even where no great talent exists in the artist, gives a unique value to his work, but which, where the intimacy is that of great minds, gives us works on which no dilettanteism, even, makes a criticism,--as in that portrait of Dante by Giotto, to our mind the portrait _par excellence_ of past time.