XV.--I say also that Being, and Unity, and the Good come in order after the fifth mode of priority.[193] For Being comes by nature before Unity, and Unity before Good. Where Being is most, there Unity is greatest; and where Unity is greatest, there Good is also greatest; and in proportion as anything is far from Being in its highest form, is it far from Unity, and therefore from Good. Therefore in every kind of things, that which is most one is best, as the Philosopher holds in the treatise about simple Being. Therefore it appears that to be one is the root of Good, and to be many the root of Evil. Therefore, Pythagoras in his parallel tables placed the one, or Unity, under the line of good, and the many under the line of Evil; as appears from the first book of the _Metaphysics_.[194] Hence we may see that to sin is nothing else than to pass on from the one which we despise and to seek many things, as the Psalmist saw when he said: "By the fruit of their corn and wine and oil, are they multiplied."[195] [Footnote 193: Arist. _Categ._, _e.g._: Priority is said in five ways--1. First in _time_. 2. First in _pre-supposition_. 3. First in _order_. 4. First in _excellence_. 5. First in _logical sequence_.] [Footnote 194: _V._ Arist. _Metaph._ 1, 5; _Ethics_ i. 4; cf. Ritter and Preller, _Hist. Philos._ sec. 105.] [Footnote 195: Ps. iv. 8 (vulg.).] Hence it is plain that whatever is good, is good for this reason, that it consists in unity. And because concord is a good thing in so far as it is concord, it is manifest that it consists in a certain unity, as its proper root, the nature of which will appear if we find the real nature of concord. Concord then is the uniform motion of many wills; and hence it appears that a unity of wills, by which is meant their uniform motion, is the root of concord, nay, concord itself. For as we should say that many clods of earth are concordant, because that they all gravitate together towards the centre; and that many flames are concordant because that they all ascend together towards the circumference, if they did this of their own free will, so we say that many men are in concord because that they are all moved together, as regards their willing, to one thing, which one thing is formally in their wills just as there is one quality formally in the clods of earth, that is gravity, and one in the flame of fire, that is lightness. For the force of willing is a certain power; but the quality of good which it apprehends is its form; which form, like as others, being one is multiplied in itself, according to the multiplication of the matters which receive it, as the soul, and numbers, and other forms which belong to what is compound.[196] [Footnote 196: On the scholastic doctrine of forms, _v._ Thom. Aquin. _Summ._ I. 105, art. 4.]