 To understand his approach to linguistics and to appreciate the empirical linguistic investigations that will follow from it, it is necessary to take a closer look at his conception of language at its formative stage where philosophy and linguistics intersect in a distinct manner. During Humboldt’s Jena period the problem of the relationship between thinking, language and reality that seemed to have been settled once and for all by rationalist (Descartes, Leibniz) and empiricist (Locke, Condillac) thinkers alike, became an open question again for Humboldt, who looked at it from the new perspective that Kantian and Fichtean philosophy had opened up. In 1795 he wrote a series of sixteen theses on On Thinking and Speaking (Ueber Denken und Sprechen, GS Vol 7: 581–83) in response to a recent essay by Fichte “On the origin of language and human language ability”. In this, his first major statement on language, he takes issue with the concept of the linguistic sign, which had been one of the cornerstones of seventeenth and eighteenth-century philosophy of language. In both the rationalist and empiricist schools of thought it was assumed that signs constituted a special class of objects outside the mind existing independently from it to which convenient labels agreed upon by society had been attached. The relationship of these signs to the mental ideas they were supposed to represent were therefore understood as “arbitrary” or “conventional”. Although empiricists and rationalists agreed that speaking required the use of signs and that without them mental operations whether they derived from sensations or not were not possible, they were unable to explain as Herder had put it, how “the sound of roundness was able to represent the idea of roundness”. But Herder himself had not been able to advance a plausible solution to the problem, either, even though he connected the origin of language with reflection (Besonnenheit), claiming that it was through reflection that humans had first created language. 