of each alternative; and disposing themselves, by the very conditions of equilibrium, into a natural hierarchy, in which the worthiest to live are in the ascendant, and the standard of life is for ever rising. What can look more like the field of a directing Will intent upon the good? Indeed, the doctrine of "natural selection" owes a large part of its verisimilitude to its skilful imitation of the conditions and method of Free-will;--the indeterminate varieties of possible movement; the presentation of these before a selective power; the determination of the problem by fitness for preference,--all these are features that would belong no less to the administration of a presiding Mind; and that, instead of resorting for the last solution to this high arbitrament, men of science should suppose it to be blindly fought out by the competing creatures, as if they were supreme, is one of the marvels which the professional intellect, whatever its department, more often exhibits than explains. (3) But, before competition can arise, there must be, besides the field of favorable possibility, _desire or instinct_ to lay hold of its opportunities. Here it is that we touch the real dynamics of evolution, which rivalry can only bring to a somewhat higher pitch. Here, it must be admitted, there is at work a genuine principle of progression, the limits of which it is difficult to fix. Every being which is so far individuated as to be a separate centre of sensation, and of the balancing active spontaneity, is endowed with a self-asserting power, capable, on the field already supposed, of becoming a self-advancing power. Under its operation, there is no doubt, increasing differentiation of structure and refinement of function may be expected to emerge; nor is there any reason, except such as the facts of natural history may impose, why this process should be arrested at the boundaries of the species recognized in our present classifications. Possibly, if the slow increments of complexity in the organs of sentient beings on the globe were all mapped out before us, the whole teeming multitudes now peopling the land, the waters, and the air, might be seen radiating from a common centre in lines of various divergency, and, however remote their existing relations, might group themselves as one family. The speculative critic must here grant without stint all that the scheme of development can ask; and he must leave it to the naturalist and physiologist to break up the picture into sections, if they must. But then, _Why_ must he grant it? Because here, having crossed the margin of animal life, we have, in its germ of feeling and idea, not merely a persistent, but a self-promoting force, able to turn to account whatever is below it; the mental power, even in its rudiments, dominating the vital, and constraining it to weave a finer organism; and, for that end, to amend its application of the chemical forces, and make them better economize their command of mechanical