The only trace surviving of these twelve Apostles is the huge blocked-out S. Matteo, now in the courtyard of the Accademia.  Vasari writes of it as follows:  “He also began a statue in marble of S. Matteo, which, though it is but roughly hewn, shows perfection of design, and teaches sculptors how to extract figures from the stone without exposing them to injury, always gaining ground by removing the superfluous material, and being able to withdraw or change in case of need.”  This stupendous sketch or shadow of a mighty form is indeed instructive for those who would understand Michelangelo’s method.  It fully illustrates the passages quoted above from Cellini and Vasari, showing how a design of the chief view of the statue must have been chalked upon the marble, and how the unfinished figure gradually emerged into relief.  Were we to place it in a horizontal position on the ground, that portion of a rounded form which has been disengaged from the block would emerge just in the same way as a model from a bath of water not quite deep enough to cover it.  At the same time we learn to appreciate the observations of Vigenere while we study the titanic chisel-marks, grooved deeply in the body of the stone, and carried to the length of three or four inches.  The direction of these strokes proves that Michelangelo worked equally with both hands, and the way in which they are hatched and crossed upon the marble reminds one of the pen-drawing of a bold draughtsman.  The mere surface-handling of the stone has remarkable affinity in linear effect to a pair of the master’s pen-designs for a naked man, now in the Louvre.  On paper he seems to hew with the pen, on marble to sketch with the chisel.  The saint appears literally to be growing out of his stone prison, as though he were alive and enclosed there waiting to be liberated.  This recalls Michelangelo’s fixed opinion regarding sculpture, which he defined as the art “that works by force of taking away.”  In his writings we often find the idea expressed that a statue, instead of being a human thought invested with external reality by stone, is more truly to be regarded as something which the sculptor seeks and finds inside his marble—­a kind of marvellous discovery.  Thus he says in one of his poems:  “Lady, in hard and craggy stone the mere removal of the surface gives being to a figure, which ever grows the more the stone is hewn away.”  And again—­

The best of artists hath no thought to show Which the rough stone in its superfluous shell Doth not include:  to break the marble spell Is all the hand that serves the brain can do.

S. Matthew seems to palpitate with life while we scrutinise the amorphous block; and yet there is little there more tangible than some such form as fancy loves to image in the clouds.