DESCARTES AND LEIBNIZ

It is often said that modern Western philosophy begins with Descartes. The German tradition of psychology certainly does, in both the general and a particular sense. Descartes turned Western philosophy inwards from metaphysical to epistemological questions and originated the idea of consciousness in its modern form. More specifically, the modifications made by Leibniz and Wolff to Descartes's system created the need for a philosophical psychology in Germany. In the Discourse on Method (1637), Descartes argued that the physical qualities and essences of Scholasticism could be dispensed with. Science should be mathematical. Bodies with measurable characteristics would replace qualities. By 1700, however, Descartes's influence was increasingly subject to criticism. The Cartesians, it was felt, had thrown out the qualities of Aristotle only to replace them with innate ideas. The tone of Enlightenment philosophy, set by Bayle and Locke, became anti-Cartesian. However, German philosophy continued to operate within a Cartesian framework. In Germany Wolff's popularity was at its height when Descartes was in eclipse in Britain and France. This is one of the reasons why the rise of psychology as a distinct discipline in the eighteenth century was confined to Germany.

The German tradition of psychology originated from a problem in Descartes. In his efforts to fend off scepticism, Descartes gave a special role to consciousness. Even if we reject all knowledge that might plausibly be doubted, we must still admit the truth of the proposition ‘I am’, for thinking requires that there be a subject that can think.