mals, it may be very difficult to say at what point intelligence begins to manifest itself; our attention is concentrated, therefore, upon those functions which appear to be the result of purely mechanical arrangements, acted upon by external stimuli. The animal becomes to our perception an automaton, and in fact, by excising some of the nervous organs last developed in its growth, we can render an adult animal an automaton, capable of performing only those habitual actions to which its brain, when in perfect condition, had educated the muscles of voluntary motion. On the other hand, commencing with the highest group in each type, and going downward, either in structural complication, or in age of individual, it is impossible to fix the limit at which intelligence ceases to be apparent.
I have in this subject, as in that of tracing the past history of our insects, in the first part of this address, preferred the latter mode of investigation; taking those things which are nearest to us in time or structure as a basis for the study of those more remote.
The second consideration is, since it is so difficult for us to understand the mental processes, whether rational or instinctive (I care not by what name they are called), of beings more or less similar but inferior to ourselves, we should exercise great caution when we have occasion to speak of the designs of one who is infinitely greater. Let us give no place to the crude speculations of would-be teleologists, who are, indeed, in great part, refuted already by the progress of science, which continually exhibits to us higher and more beautiful relations between the phenomena of Nature "than it hath entered into the mind of man to conceive." Let not our vanity lead us to believe that, because God has deigned to guide our steps a few paces on the road of truth, we are justified in speaking as if he had taken us into intimate companionship, and informed us of all his counsels.
If I have exposed my views on these subjects to you in an acceptable manner, you will perceive that, in minds capable of receiving such impressions, biology can indicate the existence of a creative or directive power, possessing attributes some of which resemble our own, and controlling operations which we may feebly comprehend. Thus far natural theology, and no further.
What, then, is the strict relation of natural history or biology to that great mass of learning and influence which is commonly called theology; and to that smaller mass of belief and action which is called religion?
Some express the relation very briefly, by saying that science and religion are opposed to each other; others, again, that they have nothing in common. These expressions are true of certain classes of minds; but the greater number of thinking and educated persons see that, though the ultimate truths taught by each are of quite distinct nature, and can by no means come in conflict, inasmuch as they have no point in common, yet so far as these truths are embodied in hu-