Nominalism has already met with due consideration. See Nominalism. The present notice will consequent- ly be confined to Realism, except so far as Nominalism and Conceptualism may be inextricably entwined with it.
I. Origin of Realism. — It would be misplaced indus- try, and inconsistent with the brevity required here, to investigate the Realist doctrines which were entertained and developed in the philosophy of the Hindus. But the mediaeval dogma is so intimately connected with the tenor of Greek speculation that a reference to its remote source in the schools of Athens cannot be avoid- ed. The controversy between Realism and Nominalism did not become predominant in speculation till the close of the 11th century, but the antagonism was distinctly declared from the times of Plato and Aristotle. The wide differences which separated the schemes of the great teacher and his greater pupil in their explana- tion of the intelligible universe (mundus intelligibilis') were plainly manifest to the successors of those great heresiarchs. The doctrine of Plato and the earnest op- position of Aristotle may be best appreciated by the careful consideration of the multitudinous passages in the text of Aristotle referred to in the index of Bonitz (Aristotelis Opera [ed. Acad. Berolin.], vol. iv) under the head of " Plato, 2." Evidences not merely of the continued antagonism of the Academic and Peripatetic schools, but also of the recognition of the gravity and the consequences of this antagonism, are abundant in the subsequent ages. It may suffice to refer to Ploti- nus (Ermead. Ill, ix, 1 ; V, v, 1 ; IX, iii, 10), to a passage in Porphyry, which will soon require to be cited, and to Hesychius Milesius (Fr. 7, ii, 53, Fragm. Eistor. Griec. iv, 173), who has stated clearly and precisely the Pla- tonic thesis ("Eori Si twv atSwv 'iv iKaarov aiCiov tb Kai vm)na Kai Trpoc, tovtoiq airaSsg. Aw icai <pnaiv iv Tij (pvou tuq iSu'ic iaravai KaSc'nrep liapaciiypara, rd o' dWa ravraiQ ioucivai, tovtwv dpotwfiaTa KaSi- OTwra). But the divergence of the schools in regard to Universale, or genera generalissimo, and to abstract notions generally, remained an indeterminate disputa- tion in the Hellenic world, and was not raised to su- preme importance till it passed, in the mediaeval period, from transcendental ontology to dialectics and theolo- gy. The germ of the grand debate is found in one of the associates of the Neo-Platonic schools, but it scarce- ly vegetated till the scholastic period. Porphyry had said, in his introduction to the Categories of Aristotle (Schol. Aristot. ap. Aristot. Opera [ed. Acad. Berolin.], iii, 1), that he would abstain from the more recondite inquiries, and aim only at a concise presentation of the simpler topics. " For," he proceeds, " I will decline to speak of the essential character of genera and species, or to inquire whether they are substantially corporeal or incorporeal, and whether they are separable or exist- ent only in perception, since this is a most profound in- vestigation, and requires other and deeper examination." The Greek of Porphyry was almost entirely unknown to mediaeval speculators, but the Latin paraphrase of Boethius was familiar to them, and constituted, as it were, a text-book of elementary logic. Thus the ques- tion of the nature of Universals was distinctly raised, and the opposite views which were entertained on the subject divided reasoners into hostile camps, and led to those passionate controversies which have been already alluded to. It was only gradually, however, that the op-
position became clear and well marked, and connected it- self closely with the gravest interests that have occupied the minds of men. In the first half of the 9th century, Rabanus Maurus, commenting on the text of Porphyry just quoted, but using the version of Boethius, recognises the conflict of opinion (Cousin, Introd.aux (Euvres Inedits oVA belard, p. 77), and is supposed to have inclined to the Nominalistic side (Caraman, Ilist.des Rev.de la Philoso- phie, i, 249). It would probably be more correct to con- clude that he sought a ground of conciliation between the two extremes. The difficult problem was, however, brought forward into distinct contemplation. If there was any tendency in Rabanus Maurus to what was af- terwards known as Nominalism, the reaction showed it- self promptly. In the next generation, the philosophy of Johannes Scotus Erigena, which was founded on an imperfect acquaintance with the Neo-Platonic teachings, ran into decided Pantheism, in accordance with the re- sults of those teachings, as developed by Plotinus. Re- garding God as the source whence all things proceed, by which all things are sustained, and to which all things return — representing creation as the self-evolu- tion of the Creator, and destruction as the self-reabsorp- tion, he rendered God all things and all things God. The basis of his whole scheme was involved in the Pla- tonic theory of ideas [see Platonic Philosophy], and in the Realist tenet universalia ante rem. Not merely were the body and spirit of Scotus's philosophy hete- rodox, but it contained several particular conclusions which were deemed heretical, and which provoked the ecclesiastical censure which they received. The Pan- theistic doctrines of Scotus Erigena naturally excited opposition when the results to which they led became apparent. If God were all things, then necessarily all things would be essentially God— being the external and phenomenal manifestations of the divine activity, and constituting, at the same time, the divine essence, inasmuch as their whole support was a real existence in the divine substance. It is the inevitable tendency of a metaphysical dogma to be unfolded by its acolytes into its ultimate logical consequences, which reveal the extravagances and the hazards of the position. It is the inevitable tendency of such revelation to arouse an- tagonism, and to suggest security in the opposite ex- treme. By such oscillation between contradictory ten- ets, the human intellect is kept from stagnation, and research and meditation are constantly stimulated. The Pantheism of Scotus Erigena annihilated independent individual existence and individual responsibility; and it obliterated the distinction between the Creator and the creation. The refutation of his errors was sought in the examination and denial of his premises, as well as in the repudiation of his conclusions. His views had been founded on the supposititious writings of Diony- sius the Areopagite, which were steeped in Neo-Pla- tonism (q. v.). Their antidote was expected from the school of Aristotle, whose logical opinions were gradu- ally disseminated throughout Western Europe, through Saracenic and Jewish channels, and which had been partially known through Boethius during nearly all mediaeval times.