And if the adversary would say, that if the desire to know the first principles of natural things is one thing, and the desire to know what they are is another, so is the desire for a hundred marks one thing, and the desire for a thousand marks is another, I reply that it is not true; for the hundred is part of the thousand and is related to it, as part of a line to the whole of the line along which one proceeds by one impulse alone; and there is no succession there, nor completion of motion in any part. But to know what the principles of natural things are is not the same as to know what each one of them is; the one is not part of the other, and they are related to each other as diverging lines along which one does not proceed by one impulse, but the completed movement of the one succeeds the completed movement of the other. And thus it appears that, because of the desire for knowledge, knowledge is not to be called imperfect in the same way as riches are to be called imperfect, on account of the desire for them, as the question put it; for in the desire for knowledge the desires terminate successively with the attainment of their aims; and in the desire for riches, NO; so that the question is solved. Again, the adversary may calumniate, saying that, although many desires are fulfilled in the acquisition of knowledge, the last is never attained, which is the imperfection of that one desire, which does not gain its end; and that will be both one and imperfect. Again one here replies that it is not a truth which is brought forward in opposition, that is, that the last desire is never attained; for our natural desires, as is proved in the third treatise of this book, are all tending to a certain end; and the desire for knowledge is natural, so that this desire compasses a certain end, although but few, since they walk in the wrong path, accomplish the day's journey. And he who understands the Commentator in the third chapter, On the Soul, learns this of him; and therefore Aristotle says, in the tenth chapter of the Ethics, against Simonides the Poet, that man ought to draw near to Divine things as much as is possible; wherein he shows that our power tends towards a certain end. And in the first book of the Ethics he says that the disciplined Mind demands certainty in its knowledge of things in proportion as their nature received certainty, in which he proves that not only on the side of the man desiring knowledge, but on the side of the desired object of knowledge, attention ought to be given; and therefore St. Paul says: "Not much knowledge, but right knowledge in moderation." So that in whatever way the desire for knowledge is considered, either generally or particularly, it comes to perfection.