The same conflict of real and unreal was shown to be essential to every natural life.  As long as anything grows it neither completely attains, nor completely falls away from its ideal.  The growing acorn is not an oak tree, and yet it is not a mere acorn.  The child is not the man; and yet the man is in the child, and only needs to be evolved by interaction with circumstances.  The process of growth is one wherein the ideal is always present, as a reconstructive power gradually changing its whole vehicle, or organism, into a more perfect expression of itself.  The ideal is reached in the end, just because it is present in the beginning; and there is no end as long as growth continues.

Now, it is evident that knowledge, whether it be that of the individual man or of the human race, is a thing that grows.  The process by means of which natural science makes progress, or by which the consciousness of the child expands and deepens into the consciousness of the man, is best made intelligible from the point of view of evolution.  It is like an organic process, in which each new acquirement finds its place in an old order, each new fact is brought under the permanent principles of experience, and absorbed into an intellectual life, which itself, in turn, grows richer and fuller with every new acquisition.  No knowledge worthy of the name is an aggregation of facts.  Wisdom comes by growth.

Hence, the assertion that knowledge never attains reality, does not imply that it always misses it.  In morals we do not say that a man is entirely evil, although he never, even in his best actions, attains the true good.  And if the process of knowing is one that presses onward towards an ideal, that ideal is never completely missed even in the poorest knowledge.  If it grows, the method of fixed alternatives must be inapplicable to it.  The ideal, whatever it may be, must be considered as active in the present, guiding the whole movement, and gradually manifesting itself in each of the passing forms, which are used up as the raw material of new acquirement; and yet no passing form completely expresses the ideal.

Nor is it difficult to say what that ideal of knowledge is, although we cannot define it in any adequate manner.  We know that the end of morality is the summum bonum, although we cannot, as long as we are progressive, define its whole content, or find it fully realized in any action.  Every failure brings new truth, every higher grade of moral character reveals some new height of goodness to be scaled; the moral ideal acquires definiteness and content as humanity moves upwards.  And yet the ideal is not entirely unknown even at the first; even to the most ignorant, it presents itself as a criterion which enables him to distinguish between right and wrong, evil and goodness, and which guides his practical life.  The same truth holds with regard to knowledge.  Its growth receives its impulse from, and is directed and determined by,