The most ignorant and careless observer cannot contemplate the works of nature without discovering many indications of the existence of general laws. Science, in its progress, has been widening the dominion of law, and has detected its presence where the unlearned saw only caprice, and where the piously disposed were accustomed to contemplate the Divine power acting independently of all instrumental causes. It is now acknowledged that there are physical laws determining every “fitful breeze, and every forming cloud, and every falling shower.” But while there is a universal recognition among the reflecting community of the existence of general laws, there is about as universal a confusion of idea as to the nature of these laws. An inquiry into this topic may help to clear away much cloudiness of conception, in which not a few errors are lurking.

“Without going into any subtilties,” says Sir John Herschell, “I may at least be allowed to suggest that it is at least high time that philosophers, both physical and others, should come to some nearer agreement than seems to prevail as to the meaning they intend to convey in speaking of causes and causation. On the one hand, we are told that the grand object of physical inquiry is to explain the nature of phenomena by referring them to their causes; on the other, that the inquiry into causes is altogether vain and futile, and that science has no concern but with the discovery of laws.