These lines, then, which he cautions us against regarding as divisions, which are brought in with such parade of scholasticism, with such a profound appearance of artifice, will always be found by those who have leisure to go below the surface, to be but the indications of those natural articulations and branches into which the subject divides and breaks itself, and the conducting lines to that trunk and heart of sciences, that common fountain from which all this new vitality, this sudden up-springing and new blossoming of learning proceeds, that fountain in which its flowers, as well as its fruits, and its thick leaves are nourished. Here in this Art of Tradition, which comprehends the whole subject of the human speech from the new ground of the common nature in man--that _double_ nature which tends to isolation on the one hand, and which makes him a part and a member of society on the other; we find it treated, first, as a means by which men come simply to a common understanding with each other, by which that _common ground_, that ground of _community_, and _communication_, and _identity_, which a common _understanding_ in this kind makes, can be best reached; and next we find it treated as a means by which _more than the understanding_ shall be reached, by which _the sentiment_, the _common sentiment_, which also belongs to the larger nature, shall be strengthened and developed,--by which the counteracting and partial sentiments shall be put in their place, and the _will_ compelled; whereby that common human form, which in its perfection is the object of the human love and reverence shall be scientifically developed; by which the particular form with its diseases shall be artistically disciplined and treated. This Art of Tradition concerns, first, the understanding; and secondly, the affections and the will. As man is constituted, it is not enough to convince his understanding.