lowing), vhieh describes arguments from effect to cause. But since Kant's day a priori has become an epithet, often polemic, applied to judgments alleged to have a validity independent of experience. Its antonym in this meaning is still a posteriori, which means resting upon experiential 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, Intuitionalists, and Criticists ( i.e., followers of Kant) maintain that many of our judgments are a priori : Empiricists deny it. The debate, however, seems to be conducted u])on a false assumption, shared by most of the protagonists on either side, viz., that experience comes piecemeal, or, technically, is atomistic in character. If such were the case, then any valid universal judgment would liave to be a priori, for no number of isolated experiences could point to a general law. But experience does not grow by the accretion of unrelated elements : rather is its growth a process of organic expansion under stimulation, which for practical purposes must be regarded as proceeding from the external world. In the knowledge thus acquired, there is the cooperation 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 consciousness. Now, these two factors may conveniently be designated the a priori and the a posteriori constituents of knowledge. But it is of the utmost 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 Understandinf!, best edition, by Fraser, 2 vols. (Oxford, 189-i) ; Leibnitz, youveatix es- sais sur I'entendement huniain, English by Langley (New York, 1896) ; also selections trans- lated by Duncan (New Haven, ISOO), and by Latta (Oxford. 1898) : D. Hume. Treatise of Hu- man Mature. Book i.. part iii. (Selby-Bigge ed., Oxford, 1888) ; id., An Enquiri/ Coneerninfi Hu- man Understanding (Selby-Bigge ed., Oxford, 1894) ; Kant, Kritik der reinen ^'crnunft. English by Max Miiller (London, 1896) ; Hegel, Enci/clo- P'iidie der philosopliischen Wissenschaften im Grundrisse (Heidelberg. 1830), in part trans- lated into English by Wallace under the titles, Hegel's Loqic (Oxford, 1892-94) and Het/el's riiilosophi/ of Mind (Oxford, 1894) ; E. H. Lotze, Logik (Leipzig. 1880), edited in English bv B. Bosanquet, 2 vols. (Oxford, 1888) ; .T. S. Slill. Logic and Examinfition of Sir W. Hamilton's Philosophi/ (London, ISfi"; last in author's life- time, 1872) ; E. Caird, A Critical Account of Ihe Philosophy of Kant. 2 vols. (New York and London. 1889) ; F.H. Bradley. Principles of Loqic (London. 1883) ; B. Bosanquet, Logic (Oxford, 1888) ; L. T. Hobhouse, Theory of Knowledge (London, 1896). See also Kant; DF.nrcTiON : Inductiox ; Logic ; Empiricism ; and Tr.^x- SCEXnKXTALISM.
ATRON (by wrong division into an apron for a. napron, O.E. napron, O.F. naperon. Fr. nap- peron. dimin. of nappe, cloth, tablecloth, from Lat. mappa, cloth, cf. napkin). An outer gar- ment, originally of linen, but often of cloth or leather, covering the front of the i)erson and in- tended to protect other clothes from injury. It is used in Coverdale's translation of the Bible (1535). and also in the Authorized Version, to render the Hebrew word ehagorah, applied to the covering of fig-leaves made by Adam and Eve after the Fall. It has also been apjilicd to va- rious mechanical devices used for purposes of protection, as ( 1 ) in military afTairs, a rectangu- lar piece of lead, with a projection on the under side, xised to cover the vents in old-fashioned cannon: (2) in ship-building, the piece of curved timber set just above the forward end of the keel, to join the several pieces of the stem and con- nect them more iirmly with the keel (see Ship- building) ; (3) in engineering structures, a plat- form placed at the base to protect it from heavy shocks; (4) in carpentry, the horizontal piece of timber which takes a carriage-piece or rough stiing on a staircase, and also the ends of joists which form the half-space or landings; (5) in plumb- ing, the lead sheeting or Hushing dressed on the slates in front of a dormer window or skylight; (6) in mechanics, the piece which holds the cut- ting tool in a planing machine; (7) in archi- tecture, a more or less flat member placed against or above anything for ))rotection, as the deco- rative member under a veran<la cornice. Besides the obvious uses of aprons in the original sense, they are also worn in elaborately decorated forms, as part of the costume of Freemasons (see Masons, Free) in the lodge; and bishops and deans in the C'hurcli of England wear an apron of black or purple silk which is an ab- breviation of the older cassock.
APSE. (For derivation, see Apsides.) An architectural term used by Greeks and Romans to designate a vaulted structiire, such as a domical chamber, or even a triumphal arch. The Romans applied it particularly to the large, semicircular niche that projected from some of their temple-cellas or their basilicas ; in the temples, it was the place for the cult-image of the god ; in the basilica, it was the prietor's tribunal, where he sat surrounded by liis assessors. In both cases it was the culminating point of the structure. The partial derivation of the Christian church or basilica from the Roman basilica or law-court makes it natural that this semi-circular projection or apse should appear as an integral part of the earliest churches; Early Church writers also called it exedra, concha, or conchula lematis. Being opposite to the facade, which usually faced west, the apse end of the church was often called the east end. The higher clergy were seated on a bench around the apse; the bishop took the prsetor's place in the centre, and the presbyters that of the assessors. The altar rose just beyond the centre of the semicircle. Being the most sacred part of the church, the apse received the richest and most artistic decoration, and the most sacred subjects were depicted upon its semidome and walls. The width of the apse usually corresponded to that of the nave of the church, whose end it seemed to form. It was not until the Seventh or Eighth century that two smaller apses were often placed on either side to stand in the same way at the ends of the aisles. They may have developed from the small sacristies which had for centuries usually been placed there.
