The principle on which we make this distinction is very clear. We judge of the design of a contrivance by its predominant tendencies and effects. If evil as often results as good, misery as often as happiness, we could not decide whether the design was benevolent or malevolent, or an indifference to both. But the benevolent tendency and effects of every natural contrivance are so obvious, and so immensely outweigh all its evil results, that we are compelled to admit the design of the Author of nature to be benevolent. And, therefore, when we see evil occasionally result from such contrivances, we are authorized to say that this is only an incidental effect; not, indeed, wholly undesigned, for we cannot doubt that God has a design in the permission of all evil. But for each particular arrangement and movement in nature we can discover a predominant and benevolent object. Take another example from the human frame. In that frame we find a multitude of organs, nearly all of which are obviously adapted to a particular use. Now, the anatomist cannot lay his finger upon one of them, and say, This was intended to produce derangement and suffering in the system. Here is a muscle contrived to clog the operations of its neighbors; here a blood-vessel adapted to corrupt the blood and produce disease; here a gland whose object is to secrete a poisonous fluid, to contaminate the whole system; here a nerve made to produce pain; here a plexus of vessels suited to bring on disease. On the contrary, this anatomist perceives at once that all the organs of the animal system, and their collocation, are fitted in the best possible manner to produce health. It is obvious at a glance that this is their design. But if such be the fact, how happens it that so few persons pass through life without disease? Is it all to be imputed to an abuse and perversion of the organs and powers of life? Not so, in my opinion. But those organs are all liable to disease; and when we see how delicate and complicated they are, we ought not to wonder that even the unavoidable causes of derangement should often bring it on. Yet, after all, health is the rule and the object, and disease only the exception. But I shall say more on this subject in another part of the argument. Some one, however, who hears me, has doubtless ere this had his thoughts recur to the organs of carnivorous animals, the poisonous fangs of serpents, and the organs of the scorpion, the tarantula, and of insects, for the generation and protrusion of deadly poison. Here we have organs expressly provided for the destruction of other animals. That such is their design, no physiologist can doubt; and hence they are intended to produce suffering, and not happiness.