But the further inference from the nerve stimulus to a cause outside of us is already the result of a false and unjustifiable application of the principle of sufficient reason. If truth alone had been the deciding factor in the genesis of language, and if the standpoint of certainty had been decisive for designations, then how could we still dare to say "the stone is hard," as if "hard" were something otherwise familiar to us, and not merely a totally subjective stimulation!

And besides, what about these linguistic conventions themselves? Are they perhaps products of knowledge, that is, of the sense of truth? Are designations congruent with things? Is language the adequate expression of all realities?