Following the lead of Adam Smith, various attempts have been made to classify taxes according as they fall upon one or the other of the different shares in distribution,— rent, interest, profits, and wages. But, Bastable has well shown, the sources from which the different taxes are paid are generally a combination of several of these. The wealth or income of very few persons consists of simply one of these shares. The attempts to carry out such classifications consistently have failed. Bastable's attempted compromise by calling such taxes as can be traced directly to one or the other shares in distribution primary, and all others secondary, brings us to practically the same results that were gained by Wagner in the discussion of direct and indirect taxes. His primary taxes are those called direct taxes above, his secondary are the indirect.

1 Political Science Quarterly, VIL, p. 717.

One other important set of distinctions must receive our attention, because it has the sanction of two prominent authorities. Wagner suggested and Cohn accepted the classification into, taxes paid out of wealth at the time of its acquisition (Erwerb) or while in possession (Besitz) or upon its consumption (Verbrauch). This distinction, according to the stage in which the tax finds the wealth from which it is paid, is often useful in showing the effects of certain taxes.

Another very valuable distinction is that made by the term "taxes on revenue." Taxes on revenue are those that fall or are assessed on the revenue, or income yielded by different kinds of property. These are a species of taxes on acquisition.

The three sets of terms which we have used in this work are : (1) direct and indirect taxes, (2) personal, property, and income taxes, (3) taxes paid on wealth at acquisition, in possession, and at the time of consumption.

Another distinction based upon the method of fixing the rate is important because of the use made of it in the American Constitution. That is the distinction between apportioned and proportioned taxes. Taxes are apportioned when the whole amount to be raised is fixed and then divided among the different tax-payers.

They are proportioned when the rate is fixed and then assessed on the base, which may be either the property or the income of the tax-payers.1