nor prove anything as to the relation of those terms to our thoughts or to existing realities. Argument is only true ex supposito. Duns Scotus, on the other hand, conceived the function of logic to deal with thoughts. As to the metaphysical basis, they were still more strongly opposed. Duns held to the reality of universals in the most uncompromising form to which the matured mediæval realism ever attained: Ockham declined to go beyond the logical necessity; he enforced the ‘law of parcimony’ (‘Entia non sunt multiplicanda præter necessitatem’) and regarded them as terms in a syllogism. It is because his view was confined to the region of logic that his doctrine is now often described as terminalism rather than nominalism. Universals were not so much names which we give to the results of our observation of many individuals more or less alike, as terms which we use to describe them for the purpose of arguing. The relation between terms and thoughts, and the relation between thoughts and facts, were both imperfect; words ultimately considered were but the signs of thoughts which were themselves signs of something else.
But if Duns and Ockham so diversely conceived the province of logic and the nature of its subject-matter, in one important respect they were led to a practical result not dissimilar. Since the days of Albert the Great there had been a gradual reaction against the earlier philosophy of the middle ages, which made the reconciliation of reason and faith its leading aim. St. Thomas Aquinas had reserved certain truths of revelation as unprovable by reason, and Duns had gone beyond him in such a way as to place theology outside the pale of the sciences. Duns's indeterminism was further extended by Ockham and the road left open for general theological scepticism. But it was only through this scepticism that he was able to retain his faith in theological dogmas, since these lay entirely beyond the possibility of human proof. In the uncertainty of intellectual processes he was forced to fall back upon the vision of faith. Morality, too, he held to be something not essential to man's nature, but (with Scotus) as founded in the arbitrary will of God.
With Ockham the sphere of logic was circumscribed, but within its limits it was the keenest of instruments. Revelation, indeed, was beyond its sphere, but it is not easy to say to what extent Ockham admitted the authority of the ecclesiastical tradition. As to the nature and power of the church, Ockham disputed with a vehement assurance doubtless born not so much of his philosophical principles as of loyalty to his order. Yet we cannot assert without qualification that he attacked the authority of the church in its strictly spiritual sphere (cf. J. Silbernagl in the Hist. Jahrb. vii. 423–33, 1886). He was indeed strongest on the critical or negative side; and while he denied the ‘plenitudo potestatis’ claimed for the papacy, he was not altogether disposed to place the emperor above the pope, nor was he happy in invoking, as was required by the controversy, the ultimate resort of a general council, even though formed alike of clergy and laymen, men and women. The infirmity of reason was with him the counterpart to the strength of the logician. He could criticise with freedom, but had scruples in reconstructing. He furnished invaluable weapons to those after him who opposed the authority of the pope, and even helped Luther in the elaboration of his doctrine concerning the sacrament; but his most enduring monument is found in the logical tradition which he established in the university of Paris. At first, in 1339, the faculty of arts forbade any one to teach his doctrine (Denifle, Chartul. Univ. Paris. vol. ii. pt. ii. pp. 485 f.); but it grew and prevailed until by the end of the century it had become the generally accepted system in the leading school of Europe. It was from his position as the first man to bring the new nominalism into wide currency that Ockham received the title of ‘Venerabilis Inceptor,’ which is apparently older than the more familiar one of ‘Doctor invincibilis.’
Ockham's logical works are: 1. ‘Summa Logices’ (ad Adamum), printed at Paris, 1488; Venice, 1522; Oxford, 1675, &c. 2. Commentaries on Porphyry's Introduction to Aristotle's ‘Organon,’ and on the earlier books of the latter, the ‘Categories,’ ‘De Interpretatione,’ and ‘Elenchi,’ partly printed at Bologna, 1496, under the title ‘Expositio aurea super totam artem veterem.’ In philosophy and theology he wrote: ‘Quæstiones in octo libros Physicorum,’ printed at Rome, 1637; and ‘Summulæ’ on the same; ‘Quæstiones in quatuor libros Sententiarum,’ printed at Lyons, 1495, &c.; ‘Quodlibeta septem,’ printed at Paris 1487, at Strassburg 1491; ‘De Sacramento Altaris’ and ‘De Corpore Christi,’ printed at the end of the ‘Quodlibeta,’ in the Strassburg edition; ‘Centilogium theologicum,’ printed at Lyons, 1495, with the ‘Quæstiones’ on the ‘Sentences;’ and several other works which remain in manuscript. Ockham's political writings have all been enumerated in his biography. To them is usually added a ‘Disputatio inter militem et clericum’ on the civil