compass, is in power and preciousness supreme.[192] Let us now see how he carries this passionate enthusiasm for knowledge into the humblest researches of zoology:— Among natural objects, some exist unchanged through all eternity, while others are generated and decay. The former are divinely glorious, but being comparatively inaccessible to our means of observation, far less is known of them than we could wish; while perishable plants and animals offer abundant opportunities of study to us who live under the same conditions with them. Each science has a charm of its own. For knowledge of the heavenly bodies is so sublime a thing that even a little of it is more delightful than all earthly science put together; just as the smallest glimpse of a beloved beauty is more delightful than the fullest and nearest revelation of ordinary objects; while, on the other hand, where there are greater facilities for observation, science can be carried much further; and our closer kinship with the creatures of earth is some compensation for the interest felt in that philosophy which deals with the divine. Wherefore, in our discussions on living beings we shall, so far as possible, pass over nothing, whether it rank high or low in the scale of estimation. For even such of them as displease the senses, when viewed with the eye of reason as wonderful works of Nature afford an inexpressible pleasure to those who can enter philosophically into the causes of things. For, surely, it would be absurd and irrational to look with delight at the images of such objects on account of our interest in the pictorial or plastic skill which they exhibit, and not to take still greater pleasure in a scientific explanation of the realities themselves. We ought not then to shrink with childish disgust from an examination of the lower animals, for there is something wonderful in all the works of Nature; and we may repeat what Heracleitus is reported to have said to certain strangers who had come to visit him, but hung back at the door when they saw him warming himself before a fire, bidding them come in boldly, for that there also there were gods; not allowing ourselves to call any creature common or unclean, because there is a kind of natural beauty about them all. For, if anywhere, there is a pervading purpose in the works of Nature, and the realisation of this purpose is the beauty of the thing. But if anyone should look with contempt on the scientific examination of the lower animals, he must have the same opinion about himself; for the greatest repugnance is felt in looking at the parts of which the human body is composed, such as blood, muscles, bones, veins, and the like.[193] Similarly, in discussing any part or organ we should consider that it is not for the matter of which it consists that we care, but for the whole form; just as in talking about a house it is not bricks and mortar and wood that we mean; and so the theory