One group of philosophers affirms, in accordance with the teleological conception, that the whole cosmos is an orderly system, in which every phenomenon has its aim and purpose; there is no such thing as chance. The other group, holding a mechanical theory, expresses itself thus: The development of the universe is a monistic mechanical process, in which we discover no aim or purpose whatever; what we call design in the organic world is a special result of biological agencies; neither in the evolution of the heavenly bodies nor in that of the crust of our earth do we find any trace of a controlling purpose--all is the result of chance. Each party is right--according to its definition of chance. The general law of causality, taken in conjunction with the law of substance, teaches us that every phenomenon has a mechanical cause; in this sense there is no such thing as chance. Yet it is not only lawful, but necessary to retain the term for the purpose of expressing the simultaneous occurrence of two phenomena, which are not causally related to each other, but of which each has its own mechanical cause independent of the other. Everybody knows that chance, in this monistic sense, plays an important part in the life of man and in the universe at large. That, however, does not prevent us from recognizing in each "chance" event, as we do in the evolution of the entire cosmos, the universal sovereignty of nature's supreme law, _the law of substance_. There is a good deal here which is less clear in the way of argument than could be wished. The famous _Law of Substance_, as we have seen, has two articles: The indestructibility of matter, and the conservation of energy. What light either of these principles may be supposed to shed on such questions as the adaptation of organs to their functions is by no means obvious. To say that there is no design in the organic world, because it is a special result of biological agencies,--is quite of a piece with the contention which has actually been made, that we can no longer argue to Design, with Paley, from the analogy of a watch, since "nearly every part of a watch is now made by inanimate machinery."[158] Thus much, however, is perfectly clear: the competence of Chance is recognized to originate a world like ours, and to enable Nature, as Professor Clifford says, seemingly to answer our questionings with an intelligence akin to our own. It would thus appear that when Newton asks,--Was the eye fashioned without knowledge of the laws of light, or the ear, without knowledge of those of sound?--we are to answer in the affirmative, and to say that such organs are but special results of biological agencies, under the general management of the Law of Substance.