History of Western Philosophy - Bertrand Russell [265]
of what we may learn from infidels. Bacon praises mathematics as the sole (unrevealed) source of certitude, and as needed for astronomy and astrology.
Bacon follows Averroes in holding that the active intellect is a substance separated from the soul in essence. He quotes various eminent divines, among them Grosseteste, Bishop of Lincoln, as also supporting this opinion, which is contrary to that of St Thomas. Apparently contrary passages in Aristotle, he says, are due to mistranslation. He does not quote Plato at first hand, but at second hand through Cicero, or at third hand through the Arabs on Porphyry. Not that he has much respect for Porphyry, whose doctrine on universals he calls 'childish'.
In modern times Bacon has been praised because he valued experiment, as a source of knowledge, more than argument. Certainly his interests and his way of dealing with subjects are very different from those of the typical scholastics. His encyclopaedic tendencies are like those of the Arabic writers, who evidently influenced him more profoundly than they did most other Christian philosophers. They, like him, were interested in science, and believed in magic and astrology, whereas Christians thought magic wicked and astrology a delusion. He is astonishing because he differs so widely from other medieval Christian philosophers, but he had little influence in his own time, and was not, to my mind, so scientific as is sometimes thought. English writers used to say that he invented gunpowder, but this, of course, is untrue.
St Bonaventura (1221–1274), who, as General of the Franciscan order, forbade Bacon to publish, was a man of a totally different kind. He belonged to the tradition of St Anselm, whose ontological argument he upheld. He saw in the new Aristotelianism a fundamental opposition to Christianity. He believed in Platonic ideas, which, however, only God knows perfectly. In his writings Augustine is quoted constantly, but one finds no quotations from Arabs, and few from pagan antiquity.
Matthew of Aquasparta (ca. 1235–1302) was a follower of Bonaventura, but less untouched by the new philosophy. He was a Franciscan, and became a cardinal; he opposed St Thomas from an Augustinian point of view. But to him Aristotle has become 'The Philosopher'; he is quoted constantly. Avicenna is frequently mentioned; St Anselm is quoted with respect, as is the pseudo-Dionysius; but the chief authority is St Augustine. We must, he says, find a middle way between Plato and Aristotle. Plato's ideas are 'utterly erroneous'; they establish wisdom, but not knowledge. On the other hand, Aristotle is also wrong; he establishes knowledge, but not wisdom. Our knowledge—so it is concluded—is caused by both lower and higher things, by external objects and ideal reasons.
Duns Scotus (ca. 1270–1308) carried on the Franciscan controversy with Aquinas. He was born in Scotland or Ulster, became a Franciscan at Oxford, and spent his later years at Paris. Against St Thomas, he defended the Immacu late Conception, and in this the University of Paris, and ultimately the whole Catholic Church, agreed with him. He is Augustinian, but in a less extreme form than Bonaventura, or even Matthew of Aquasparta; his differences from St Thomas, like theirs, come of a larger admixture of Platonism (via Augustine) in his philosophy.
He discusses, for example, the question 'Whether any sure and pure truth can be known naturally by the understanding of the wayfarer without the special illumination of the uncreated light?' And he argues that it cannot. He supports this view, in his opening argument,