Aristotle

I

Introduction

Aristotle (384-322 bc), Greek philosopher and scientist, who shares with Plato and Socrates the distinction of being the most famous of the ancient philosophers. Born at Stagira, in Macedonia, the son of a physician to the royal court, Aristotle moved at the age of 17 to Athens to study at Plato’s Academy. He remained there for about 20 years, first as a student and then as a teacher.

When Plato died in 347 bc, Aristotle moved to Assos, a city in Asia Minor, where a friend of his, Hermias, was ruler. There he counselled Hermias and married his niece and adopted daughter, Pythias. After Hermias was captured and executed by the Persians in 345 bc, Aristotle moved to Pella, the Macedonian capital, where he became tutor to the king’s young son Alexander, later known as Alexander the Great. In 335 bc, when Alexander became king, Aristotle returned to Athens and established his own school, the Lyceum. Because much of the discussion in his school took place while teachers and students were walking about the Lyceum grounds, it came to be known as the Peripatetic (“walking” or “strolling”) school. Upon the death of Alexander in 323 bc, strong anti-Macedonian feeling developed in Athens, and Aristotle retired to a family estate in Euboea. He died there the following year.

II

Works

Aristotle was a prolific writer. He wrote a vast number of works on a wide range of topics. Three ancient catalogues credit him with having written more than 170 separate texts, although it is likely that a significant number of these are false attributions. Like Plato, Aristotle published philosophical dialogues. However, apart from a few fragments in the works of later writers, his dialogues have been wholly lost. He also wrote summaries of the works of other philosophers, and is credited with works on topics as diverse as music and optics, and a book of proverbs. Of these, only a few brief excerpts have survived. Still in existence, however, is a substantial body of unpublished writings, usually taken to be the material on which courses in the Lyceum were based. These works were collected, arranged, and given titles by later editors, the first of whom was Andronicus of Rhodes, the last head of the Lyceum, who put together and published an edition of them c. 60 bc, over 200 years after Aristotle’s death. This edition provided the body of Aristotelian work on which so much of the later history of Western philosophy would be based.

As regards the traditional conception of the arrangement of Aristotle’s works, his treatises on logic came first. These became collectively known as the “Organon” (meaning “instrument” or “tool”), because they provided the requisite tools for gaining philosophical understanding. Next came a series on nature, including the Physics, in which Aristotle set out the principles that explain the natural world. Aristotle also wrote a number of detailed accounts of particular aspects of the natural world, including studies of the anatomy of animals, natural processes of generation and corruption, and astronomy and meteorology. After his writings on nature came a work in what Aristotle calls “first philosophy”, the philosophical study of being. Its traditional Greek title indicates its place in the series as “the works after the physics” (“Ta Meta ta Phusika”); from this originated the term “metaphysics”. To his son, Nicomachus, Aristotle dedicated his principal work on ethics, known therefore as the Nicomachean Ethics. Other important texts include the Rhetoric, the Poetics (which survives in incomplete form), and the Politics (also incomplete).

III

Methods

Aristotle had great confidence in human beings’ ability to arrive at a reasoned understanding of the world around them. He was committed to the claim that the world itself makes understanding possible; that it is structured in such a way as to be amenable to rational inquiry and understanding. Further, the nature of human beings is to have both the capacity and the desire to understand the world. Thus, the world and human nature cooperate in making understanding possible.

Aristotle maintained that although human beings are born with a capacity to understand the world, they are not born with such an understanding already in place. This raises the question of how such an understanding is to be attained. The data with which the journey to understanding begins is in part given by sense perception. Repeated perceptions, for example, of individual human beings, stored in memory, enable people to grasp what it is that human beings have in common as human beings. To understand this is to understand the universal human being, embodied in particular human beings such as Plato and Socrates.

For Aristotle, a full understanding of what human beings have in common requires an understanding of the essence of a human being, that is, what in any individual is responsible for their characteristic features as a member of the natural kind, “human beings”. To understand the essence of a human being is to grasp the explanatory principle of human beings as such. This explanatory principle is reached as the last stage of the progress of inquiry; but it is first in the order of explanation. The individuals perceived in the world are readily accessible, and can therefore initiate the progress towards understanding; but they are not self-explanatory. Only by arriving at an understanding of essence is it possible to understand something in a way that is not itself in need of further explanation.

In particular branches of philosophy, for example, relating to astronomy or ethics, the data for inquiry is provided not only by sensory experience, but also by the results of the inquiries of previous thinkers. Aristotle’s confidence both in the ultimate intelligibility of the world and in the human capacity for understanding led him to believe that someone who has thought seriously about philosophical matters will have achieved some grasp of the truth. Philosophical progress may therefore be made by beginning with the views of others. Many of Aristotle’s own works begin with a survey of the “reputable opinions” (endoxa) on the subject in question. What count as reputable opinions are opinions held by everyone or almost everyone; or opinions held by the wise, whether all, the majority, or only the most noteworthy of the wise. Inevitably, these opinions conflict with each other. Since, however, every reputable opinion contains some partial truth, by identifying and resolving the source of the conflict between the views of previous thinkers, one may arrive at an understanding of the broader truth of which the previous thinkers had a partial grasp.

IV

Nature

Aristotle’s philosophical writings bear witness to his interest in the natural world. Perhaps the most fundamental part of his philosophy is his analysis of natural or living things, that is, plants and animals, including human beings. In Aristotle’s view, the natural world is made up of individual plants and animals occurring in fixed natural kinds or species. He denied that the natural world is the product of a historical creation or the result of some evolutionary process. The defining characteristic of natural or living things is that they are subject to change: the regular processes of birth, growth, development, and decay that can be observed in the natural world.

Aristotle argued that what explains these natural recurring processes of change is the nature of a living thing such as a plant or animal. Natural things, which exist in nature, have a nature—an internal dynamic principle responsible for the specific pattern of development that each member of a natural species undergoes—consisting of two aspects: a material aspect and a formal aspect. The material aspect is the material of which the plant or animal is composed, and which enables the relevant processes of development to occur, that is, the “matter” of the plant or animal. The formal aspect of the nature of a living thing is its identity as the specific kind of thing it is, which, in combination with the requisite matter, governs the development of the individual as a member of the natural species. This formal aspect is the “form” of the plant or animal. So, if one seeks to understand the development of an acorn into an oak tree, one must understand not only the material processes involved, but also that these material processes occur precisely because they are the material processes necessary for the development of an acorn into an oak tree, and constitute its development as such. For Aristotle, the developmental processes of an acorn could only be understood in relation to the fact that the acorn is developing into an oak tree, that is, into a mature member of the species oak. His analysis of natural processes was thus teleological, since natural processes can only be explained in terms of the end or goal to which they are directed.

From this analysis of the nature of a living thing came Aristotle’s account of the explanatory factors involved in natural change. He identified four such factors, each of which involved either the material or formal aspect of the nature of a living thing. They are (1) the “material cause”, the matter of a living thing; (2) the “formal cause”, its form; (3) the “efficient cause” or the “origin of the change”, the male parent of the living thing in question, which transmits the form in reproduction and thereby initiates the developmental process; (4) the “final cause”, the fully developed living thing, which, as an adult member of its species, has achieved the end to which its earlier processes of development were directed. This end is the realization of form—the identity of the living thing as a member of its species—in the appropriate matter. Of these four explanatory factors, the third—the “efficient cause”—is most readily confused with more modern notions of causation. The requirement that each natural process of development be initiated by an adult member of the species in question is better understood as evidence of Aristotle’s commitment to supposing that the chicken must have come before the egg. His reasons for supposing this were complex, and are set out in Book 8 of the Physics.