create knowledge in us are the pleasantest." Aristotle's writings on metaphor constitute a "substitution view" of metaphor, wherein a metaphor is simply a decorative word or phrase substituted for a more ordinary one. This has been sometimes called the "Traditional View of Metaphor" and at other times the "Classical Theory of Metaphor". Later in the first century A.D., the Roman rhetorician Quintilian builds upon Aristotle's earlier work of metaphor by focusing more on the comparative function of metaphorical language. In his work Institutio Oratoria, Quintilian states," In totum autem metaphora brevior est similitudo" or "on the whole, metaphor is a shorter form of simile". Other philosophers throughout history have lent their perspectives to the discussion of metaphor as well. Friedrich Nietzsche for example, claimed that language as a whole did not portray reality but instead made a series of bold metaphors. Nietzsche believed that each step of cognition, the transfer of real world information to nerve stimuli, the culmination of nerve stimuli into mental images, the translation of mental images to words, was metaphorical. Modern interpretations of these early theories have also been intensely debated. Janet Soskice, Professor of Philosophical Theology at the University of Cambridge, writes in summary that "it is certain that we shall taste the freshness of their insights only if we free them from the obligation to answer questions that were never theirs to ask". George Lakoff and Mark Johnson, although originally taking a hard-line interpretation of these early authors later concede that Aristotle was working within a different philosophical framework from what we engage with today and that critical interpretations should take this in to account. Modern In his 2007 book The Stuff of Thought, cognitive scientist Steven Pinker lays out several useful classifications for the study of conceptual metaphor. Pinker first contrasts two perspectives on metaphor, what he calls the killjoy theory and the messianic theory. The killjoy theory categorizes metaphors as "dead", that is it asserts that modern day speakers are not aware of the comparison made between source and target domains in the everyday metaphors they use. For example, many are not cognizant that the phrase "to come to a head" refers to the accumulation of pus in a pimple. In contrast, the messianic theory correlates more closely with Lakoff and Johnson's idea of a conceptual metaphor. This view states that users of metaphors are aware of how the metaphor maps onto