ABSTRACT
If we regard the phenomena of nature which surround us, as well as those of social life, we shall observe that these phenomena by no means constitute a confused mass in which nothing may be distinguished or understood or predicted. On the other hand, we may everywhere ascertain, by attentive observation, a certain regularity in these phenomena. Night is followed by day; and, just as inevitably, day is followed by night. The seasons regularly follow one upon the other, accompanied by a great number of concomitant phenomena, repeating themselves year after year; the trees put forth their leaves and shed them; various kinds of birds of passage fly into our country and out again; men sow or reap; etc. Whenever a warm rain falls, mushrooms grow up in profusion, and we even have a saying, “to grow like mushrooms after a rain.” A grain of rye, falling upon the ground, will strike root and the plant under certain circumstances will ultimately produce an ear of grain. But we have never observed that any such ear grew—let us say—out of frogs' eggs or from bits of sandstone. Everything in nature, therefore, from the movements of the planets down to the little grain or mushroom, is subject to a certain uniformity or, as it is generally put, to a certain natural law.
