Abstraction in Aristotle and Aquinas

INTRODUCTION

The source of human knowledge has been one of the major preoccupations of philosophers over the ages. The attempt to find out where human knowledge comes from has led to diverse views. Some believe that human knowledge comes from experience and that human beings are born tabula rasa, that is, the human mind at birth is blank. Others believe that human beings do not acquire knowledge from experience; rather human beings are born with knowledge, which is referred to as the innate ideas.

However, Aristotle and St. Thomas Aquinas are among the philosophers who believe that human beings acquire knowledge through sense experience or rather sense perception. It was Aristotle who first introduced the idea of the process of abstraction in explaining the source of human knowledge. The theory of abstraction was also embraced by St. Thomas Aquinas. They both held the view that human beings are born without any ideas in their minds, man only knows through the process of abstraction of the essences of particular things and forming them into universal ideas.

The doctrine of abstraction has received a lot of criticism from many philosophers. One of the notable critics of abstraction was George Berkeley. According to Berkeley, abstraction is instrumental to the practice of a kind of transcendentalism which has no existential status, yet giving the deceitful impression of concrete existence. For Berkeley, the only things that exist are particular things; to talk of abstract general idea is an existential aberration. He therefore describes abstracted entities as involving metaphysics without ontology.[1]  

The aim of this paper is to look into what Aristotle and Aquinas thought about abstraction. To do this, I shall first define the meaning of the term abstraction and the types of abstraction. Second, I will consider the different views of philosophers about universal since abstract ideas are also universal ideas. Among those views to consider are Exaggerated Realism, Nominalism and Moderate Realism. And finally, the thoughts of Aristotle and Aquinas on   abstraction will be explicated.

MEANING OF ABSTRACTION1.1       What is Abstraction?

The term ‘abstraction’ is the usual expression in medieval philosophical terminology for several processes distinguished in Aristotle’s writings by different terms, viz., aphaeresis and korismos described in different ways. It was Boethius, most probably, who introduced the Latin abstractio and abstahere to translate these Greek nouns and related verbs.[2] Abstraction is a philosophical process by which people develop concepts either from experience or from other concepts. Abstraction is the process of drawing out the essence of things and giving them independent existence from the things of which they are inextricably connected.  It is also seen as a process whereby qualities are drawn from particular object and given a universal application. However, in this process a quality is abstracted and made to stand as a generic term housing a class of objects. For instance, when we  use the generic term ‘man’ we have merely extracted the essence of all men and have made it to stand for the general idea of collectivity of men.[3]