169 The word method is used in an essentially different sense, when the inquiry is, whether the inductive or deductive method is followed in Political Economy. _J. S. Mill_ calls Political Economy, and, indeed, all “sociology,” a concrete deductive science, whose _a priori_ conclusions, based on the laws of human nature, must be tested by experience, either by comparing them with the concrete phenomena themselves, or with their emperical laws. It, in this, resembles astronomy and physics. (System of Logic VI, ch. 9. Essays on some unsettled questions of Political E., No. 5.) According to this, an economic fact can be said to have received a scientific explanation only when its deductive and inductive explanations have met and agreed. “Only those principles which, after they have been obtained by the one, are confirmed by the other method, can be said to have a scientific basis.” (_von Mangoldt_, Grundriss, 8.) While I agree to this view, it seems necessary to me to mention points wherein caution is necessary: A. Even the deductive explanation of economic facts is based on observation, namely, on the self-observation of the person accounting for them, who, consciously or unconsciously, must always inquire: If I had experienced or accomplished the same fact, what should I have thought, willed and felt? The man who cannot translate himself into the souls of others, will give a wrong explanation of most economic facts. In the question, for instance, of the determination of the price of an article, the person who can look into the mind of one of the contracting parties only, will give a one-sided explanation of the facts. B. Moreover, every explanation, that is, satisfactory connection of the fact seeking explanation with other facts which are already clear, can be only provisional. The wider our horizon grows, the deeper should our solution of all questions become. A hundred years hence, should science increase in the mean time, the solutions which are satisfactory to us will be looked down upon by our posterity, as the speculations of our fathers antecedent to Adam Smith’s time are looked down upon by us.