The Philosophical Review/Volume 1/Summary: Dessoir - Des Nic. Tetens Stellung in der Geschichte der Philosophie
Many contradictory world-conceptions obtained following during the time in which Tetens wrote. Central among these was that of the Wolfian school, opposed by the Empiricists and the theological Crusians, and surrounded by the Eclectics, Materialists, Skeptics, and Popular-philosophers. Tetens is distinguished from the Leibnitz-Wolfian school by his treatment of sensation, presentation, and the 'faculties.' He accepts 'unperceived presentations' as the active source of psychical life, but restricts the term 'presentation' to "traces remaining after the occurrence of changes in soul-life, and relating to those changes." Memory-images are included; but states of feeling, as such, are not presentations, though they become so through their results. While the common notion reduced all psychical phenomena to presentations, and yet named several 'chief psychical states,' Tetens rested his classification of faculties on no distinction of important states, but on the double power of the soul, receptivity and spontaneous activity. Instead of thinking and representing, he put forward willing and knowing as the forms of spontaneity, knowledge including both thought and representation. He neglected Wolfs doctrine of after-images, and substituted conclusions of his own, which anticipate the result of recent physiologists. His work is characterized by careful observation and research instead of by verbal subtleties; and when he did not differ from current conceptions, he rendered them more exact and significant. With the Eclectics Tetens had little in common, rejecting their limitless glorification of the emotions, particularly the moral sense, neglecting their favorite inquiries into animal psychology and the life-force, and keeping clear of their tone of sentimentality and their overestimate of English philosophy. He took a step forward in the theory of feeling, distinguishing by the term 'sensation' that which has objective reference, while 'feeling' referred to that "beyond which I know nothing except that it is a change in me." Above all, he pointed out the weakness of the attempt made by English philosophers to explain all psychical processes by the laws of association. Tetens held himself aloof from the theological discussions of Rüdiger and Crusius, but he developed the former's Empiricism, and his epistemology recalls the latter's distinction between the synthetic and the analytic functions, with the relating of phenomena through the causal nexus as an example of synthesis. In discussing the problem of time and the outer world, Tetens pointed out the inadmissibility of the appeal made by the Popular-philosophy to the judgments of common sense. Against the Skeptics, he used in Wolfian fashion the Principle of Sufficient Reason with the result of falling into the usual confusion between cause and reason. He was more successful in combating the Materialists, whose identification of psychical processes with movements in the brain he declared to escape all tests and to be worthless as an explanation of the facts. The Kantian doctrines concerning time and space and the a priori forms lay before Tetens as he wrote his chief work, and it is probable that the Philosophische Versuche had a reciprocal influence upon Kant himself. The relation between the two philosophers is shown in the fact that Tetens gave to epistemological considerations a far more independent place than they had hitherto gained. He inquired after the conditions of experience; and if his results cannot be compared with those of Kant, it is evident that his aim was the same. Both philosophers recognized the same distinction between understanding and sensibility, and Tetens was in advance of the K. d. r. V. in denying the possibility of grounding knowledge of phenomena in sensibility, and knowledge of things in pure reason. While Tetens held regularity in the succession of phenomena to be a priori, Kant allowed apriority only to the concept of cause in general. In his doctrine of time and space Tetens was much behind Kant, being unable to free himself from the notion that these were determined by relations of presentations, although, according to the teaching of Criticism, only the boundaries of an already given time and space are so determined. Tetens was a voluminous writer, but a keen and able thinker. His place in the history of philosophical schools is that of an anti-materialistic Empiricist with critical inclinations.