Metaphysical Issue 2:  Plato Aristotle  

          Plato makes the case that forms exist apart from matter. Geometric forms—such as squares and circles—can be envisioned as perfect in one’s mind. Plato goes on to say that many other forms can also be envisioned: beauty, truth, and goodness, including the form of the good person or good society. Both the form and its physical representation, according to Plato, truly exist. Further, we are born with these ideas.

          Aristotle holds that forms are the products of our experiences in this world. He denies the existence of a separate world of ideas and contends that we “form” ideas of circles and so forth from our experience of particular circles. We abstract, as it were, from our experience of round objects to the notion of a circle.

          STRENGTH: The position of Plato is attractive to many people, especially to those who entertain the prospects of another, nonphysical world. Many who subscribe to official or orthodox Christianity are drawn to Plato’s position as interpreted by his followers—such as Augustine—in the Christian era.

          The strength of Aristotle’s position is its appeal to those who have a more practical orientation. Rather than building his model of nature on speculation about another, nonphysical world, Aristotle begins with what we can know for practical purposes. He then bases his claims about what we ought to do on his observations of the functions or potentials of each type of thing that he observes. We actualize our potentials, he says, and in doing so discover the forms that lie within us.

          WEAKNESS:  The main criticisms of Plato come from the Aristotelian tradition. Aristotle and his followers hold that Plato’s theory of reality is too complicated. Instead of positing two worlds, Aristotle argues, it is simpler to posit one world—namely, the world of our experience. It is also more plausible, according to Aristotle, to claim that our ideas come from experience rather than from another world—the world of ideas in Plato’s proposal—where we dwell before entering the physical body.

          The criticisms of Aristotle come from mainly from the liberal tradition. Kant agrees with Aristotle that matter and form are principles rather than things, but Kant also holds that more concepts can be included in the list. Besides matter and form, according to Kant, God, self, and freedom may be regarded as ideas that we use to help make sense of the flow of experience. These too are principles rather than things.