A PRIORI (Lat., froni something prior, foregoing, a. from. and prior, prior). In Aris totelian terminology, a designation applied to arguments from cause to effect, as opposed to a posteriori (Lat., from something posterior, fol lowing), which describes arguments from effect to cause. But since Kant's day a priori has be come an epithet, often polemic, applied to judg ments alleged to have a validity independent of experience. Its antonym in this meaning is still a posteriori, which means resting upon experi ential proof. The attitude one takes toward the question of the possibility of a priori judgments is one of the most crucial tests of one's affiliation among the philosophic schools. Rationalists, In tuitionalists, and Criticists (i.e., followers of Kant) maintain that many of our judgments are a priori; Empiricists deny it, The debate, how ever. seems to be conducted upon a false assuthp tion, shared by most of the protagonists on either side, viz., that experience conies piecemeal, or, technically, is atomistic in character. If such were the ease, then any valid universal judgment would have to be a priori, for no number of iso lated experiences could point to a general law. But experience does not grow by the accretion of unrelated elements; rather is its growth a proc ess of organic expansion under stimulation, which for practical purposes mint be regarded as pro ceeding from the external world. In the knowl edge thus acquired, there is the co6peration of what may be distinguished as two factors, the nature of consciousness and the nature of the stimulus that gives rise to a content in conscious ness. Now, these two factors may conveniently be designated the a priori and the a posteriori constituents of knowledge. But it is of the ut most moment to guard against the error of sup posing that antecedently to experience there is a thing called mind which comes to the act of ex perience ready equipped with either a determi nate nature or with full-blown knowledge of some sort. The literature of the subject is enor
mous. Omitting all reference to ancient phi losophers, some of the noteworthy books bear ing on the topic are: J. Locke, Essay Concerning Human Understanding, best edition, by Fraser, 2 vols. (Oxford, 1894) ; Leibnitz, Nourcaus es sais ser l'entendement humain, English by Langley (New York, 1S96) ; also selections trans lated by Duncan (New Haven, 1890), and by Latta (Oxford. 1898) ; D. Hume, Treatise of Hu man Nature, Book i., part iii. (Selhy-Bigge Oxford, 1888) ; id., An Enquiry Concerning Hu man Understanding (Selby-Bigge ed., Oxford, 1S94) ; Kant, Kritik der reinenlernanft, English by Maxller (London, 1896) ; Hegel, Eneyclo piidie der philosophisehen Wissenschaf ten int. Grundrisse (Heidelberg, 1830), in part trans lated into English by Wallace under the titles, ilegrPs Logic (Oxford, 1892-94) and //cllers Philosophy of Mind (Oxford, 1894) ; E. H. Lotze, Logik (Leipzig• 1S80), edited in English by B. Bosanquet, 2 vols. (Oxford, 1883) ; .1. S. Shill. Logic and Examination of Sir W. Hamilton's Philosophy (London, IS67; last in author's life time, 1872) ; E. Caird, A Critiral ,Icreont of the Philosophy of Kant, 2 vols. (Ne• York and London, 1S89) ; ED. Bradley. Principles of Logic (London, 1883) ; B. Bosanquet, Logic (Oxford. ; L. T. Dobhouse, Theory of Knowledge (London, 1896). See also KANT; DEDUCTION; INDUCTION; LOGIC; EMPIRICISM; and TRAN SCENDENTALISM.