Czolbe Heinrich (1819–73), German philosopher. He was born in Danzig and trained in theology and medicine. His main works are Neue Darstellung des Sensualismus (‘New Exposition of Sensualism,’ 1855), Entstehung des Selbstbewusstseins (‘Origin of Self-Consciousness,’ 1856), Die Grenzen und der Ursprung der menschlichen Erkenntnis (‘The Limits and Origin of Human Knowledge,’ 1865), and a posthumously published study, Grundzüge der extensionalen Erkenntnistheorie (1875). Czolbe proposed a sensualistic theory of knowledge: knowledge is a copy of the actual, and spatial extension is ascribed even to ideas. Space is the support of all attributes. His later work defended a non-reductive materialism. Czolbe made the rejection of the supersensuous a central principle and defended a radical ‘sensationalism.’ Despite this, he did not present a dogmatic materialism, but cast his philosophy in hypothetical form. In his study of the origin of self-consciousness Czolbe held that dissatisfaction with the actual world generates supersensuous ideas and branded this attitude as ‘immoral.’ He excluded supernatural phenomena on the basis not of physiological or scientific studies but of a ‘moral feeling of duty towards the natural world-order and contentment with it.’ The same valuation led him to postulate the eternality of terrestrial life. Nietzsche was familiar with Czolbe’s works and incorporated some of his themes into his philosophy. See also SENSATIONALIS. G.J.S. d’Ailly, Pierre (1350–1420), French Ockhamist philosopher, prelate, and writer. Educated at the Collège de Navarre, he was promoted to doctor in the Sorbonne in 1380, appointed chancellor of Paris University in 1389, consecrated bishop in 1395, and made a cardinal in 1411. He was influenced by John of Mirecourt’s nominalism. He taught Gerson. At the Council of Constance (1414–18), which condemned Huss’s teachings, d’Ailly upheld the superiority of the council over the pope (conciliarism). The relation of astrology to history and theology figures among his primary interests. His 1414 Tractatus de Concordia astronomicae predicted the 1789 French Revolution. He composed a De anima, a commentary on Boethius’s Consolation of Philosophy, and another on Peter Lombard’s Sentences. His early logical work, Concepts and Insolubles (c.1472), was particularly influential. In epistemology, d’Ailly contradistinguished ‘natural light’ (indubitable knowledge) from reason (relative knowledge), and emphasized thereafter the uncertainty of experimental knowledge and the mere probability of the classical ‘proofs’ of God’s existence. His doctrine of God differentiates God’s absolute power (potentia absoluta) from God’s ordained power on earth (potentia ordinata). His theology anticipated fideism (Deum esse sola fide tenetur), his ethics the spirit of Protestantism, and his sacramentology Lutheranism. J.-L.S.