Page:History of Modern Philosophy (Falckenberg).djvu/205

NA TURAL PHILOSOPH Y AND PS YCHOLOG Y. I S3 the senses, God has all things in himself, is immediately- present in all, and cognizes them without sense-organs, the expanse of the universe forming his sensorium. The transfer of mechanical views to psychical phenomena was also accompanied by the conviction that no danger to faith in God would result therefrom, but rather that it would aid in its support. The chief representatives of this movement, which followed the example of Gay, were the physician, David Hartley* (1704-57), and his pupil, Joseph Priestley, fa dissenting minister and natural scien- tist (born 1733, died in Philadelphia 1804; the discoverer of oxygen gas, 1774). The fundamental position of these psychologists is ex- pressed in two principles : ( i) all cognitive and motive life is based on the mechanism of psychical elements, the highest and most complex inner phenomena (thoughts, feelings, volitions) are produced by the combination of simple ideas, that is, they arise through the " association of ideas ** ; (2) all inner phenomena, the complex as well as the simple, are accompanied by, or rather depend on, more or less compli- cated physical phenomena, viz., nervous processes and brain vibrations. Although Hartley and Priestley are agreed in their demand for an associational and physiological treat- ment of psychology, and in the attempt to give one, they differ in this, that Hartley cautiously speaks only of a parallelism, a correspondence between mental and cerebral processes, and rejects the materialistic interpretation of inner phenomena, pointing out that the heterogeneity of motion and ideas forbids the reduction of the latter to the former, and that psychological analysis never reaches cor- poreal but only psychical elements. Moreover, it is only with reluctance that, conscious of the critical character of ♦Hartley, Observations on Man, his Frame, his Duties, his Expectations. 1749- ■f Priestley, Hartley's Theory of the Human Mind on the Principles of the Association of Ideas, 1775 ; Disquisitions relating to Matter and Spirit, 1777 ; The Doctrine of Philosophical Necessity, 1777 : Free Discussions of the Doc- trines of Materialism. 1778 (against Richard Price's Letters on Materialism and Philosophical Necessity). Cf. on both Schoenlank's dissertation, Hartley und Priestley, die Begriinder des Assoziationismtts in England, 1882.