2. But in a cranny or cleft of the same there is a little flower growing. You cannot do what you will with that flower. It has its exigencies and requirements. Had it a voice, it could say, what the stone never could: "I must have this or that: I must have light, I must have moisture, a certain heat, some soil to grow in." There is a course to be run by this flower and the plant that bears it, a development to be wrought out, a perfection to be achieved. For this end certain conditions are necessary, or helpful: certain others prejudicial, or altogether intolerable. In fact, that plant has a _progressive nature_, and therewith is a subject of good and evil. Good for that plant is what favours its natural progress, and evil is all that impedes it. 3. All organic natures are progressive: that is, each individual of them is apt to make a certain progress, under certain conditions, from birth to maturity. But man alone has his progress in any degree in his own hands, to make or to mar. Man alone, in the graphic phrase of Appius Claudius, is _faber fortunæ suæ_, "the shaper of his own destiny." Any other plant or animal, other than man, however miserable a specimen of its kind it finally prove to be, has always done the best for itself under the circumstances: it has attained the limit fixed for it by its primitive germinal capacity, as modified by the events of its subsequent environment. The miserable animal that howls under your window at night, is the finest dog that could possibly have come of his blood and breeding, nurture and education. But there is no man now on earth that has done all for himself that he might have done. We all fall short in many things of the perfection that is within our reach. Man therefore needs to stir himself, and to be energetic with a free, self-determined energy to come up to the standard of humanity. It is only his free acts that are considered by the moralist. Such is the definition of Moral Science, that it deals with _human acts_; acts, that is, whereof man is master to do or not to do. (c. i., nn. 1, 2.)