Friedrich Nietzsche challenges human intellect in his essay “On Truth and Lies in an Extra-Moral Sense,” by claiming that knowledge is simply an invention of the individual that deceives rather than guides us to the actual truth. Because knowledge is a human creation, Nietzsche concludes that truth and lies are also manmade concepts and are therefore false and illogical. This idea of “truth” he therefore defines as “a mobile army of metaphors…a sum of human relations which have been enhanced…and after long use seem firm, canonical, and obligatory to a people.” (Contradicting to Descartes belief of certainty and truth).

I found Nietzsche’s assessment of the validity of language to be intriguing. He argues that language is unable to capture the true nature of reality. He describes language as metaphoric because a word is simply a nerve stimulus transferred to an image and then copied in sound. These metaphors cannot grasp the essence of objects or entities. He emphasizes how language generalizes experiences which disconnects the experience from the words. He also finds language to be subjective because it did not originate from truth and certainty. He states, “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.” Because “hard” is a subjective stimulation, to say “the stone is hard” would be an illusion. Due to the fact that Nietzsche finds language as metaphoric and arbitrary (and meaningless), there seems to be no sense of certainty. Humans can never actually know the truth. Although Nietzsche makes a strong argument about truth and language, I find it to be problematic. Is finding truth even possible?

Nietzsche also argues that human ability to categorize concepts creates a false sense of truth. When explaining how humans that encounter a leaf may be able to categorize it from previous experiences (leaf prototype), he argues that this may be problematic because this categorization (language) does not capture the leafs individuality (essence). He claims that “we obtain the concept by overlooking what is individual and actual.” He thus concludes that both language and concepts are deceptive and cannot lead us to the truth.