The sun rises in the east. The boy throws a stone through the window. A democratic wave sweeps the country. Prices of food stuff are high. The bullet, shot out into space, finally falls to the earth. Each one of these occurrences has a cause.[12] That universal causation is a fundamental condition of all induction may be further illustrated. The astronomer notes that the stars in the vicinity of Vega seem to be moving outward _from_ a common center; whereas in the opposite part of the sky the stars seem to be moving inward _toward_ a common center. Having observed this phenomenon, the astronomer at once looks for a cause. Finally he decides that the phenomenon is due to the fact that the sun, with his attending family, is moving towards Vega. Arranged, the argument may take this form: The stars in the vicinity of Vega seem to be moving outward from a common center, whereas in the opposite part of the sky the stars seem to be moving inward, When descending a mountain the trees at the foot seem to move outward from, and those at the top inward toward, a common center, When riding on the train the ties in front seem to move outward while those in the rear seem to move inward. From this we conclude that the sun with the Earth and other planets is moving toward a spot in the sky near Vega. Were it not for the assumption that the phenomenon relative to the stars _had a cause_ there could have been no induction. Moreover, any investigation concerning “democratic waves,” “prices of food stuffs,” etc., must assume as a starting point that these phenomena have causes. It would appear that the mind is not satisfied with a mere passive observation of the occurrences of the world but is inclined to reach out for the “whys and wherefores.” Due partly to this reason, “universal causation” is often referred to as an _a priori_ law; meaning that it is a law which cannot be _proved_, but must be _assumed_ in all thinking. =8. THE LAW OF THE UNIFORMITY OF NATURE.= Law stated: _The same antecedents are invariably followed by the same consequents._ “That the course of nature is uniform is the fundamental principle of induction.”――Mill. “It is not enough to feel assured that nothing can happen without a cause (causation); I must also feel assured that the same cause will invariably be followed by the same effect.”――Fowler.