Wednesday 21 December 2011

Aristotle's scientific method

Aristotle

Aristotle (Greek: Ἀριστοτέλης, Aristotélēs) (384 BC – 322 BC) was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology. Together with Plato and Socrates (Plato's teacher), Aristotle is one of the most important founding figures in Western philosophy. Aristotle's writings were the first to create a comprehensive system of Western philosophy, encompassing morality and aesthetics, logic and science, politics and metaphysics.
Aristotle's views on the physical sciences profoundly shaped medieval scholarship, and their influence extended well into the Renaissance, although they were ultimately replaced by Newtonian physics. In the zoological sciences, some of his observations were confirmed to be accurate only in the 19th century. His works contain the earliest known formal study of logic, which was incorporated in the late 19th century into modern formal logic. In metaphysics, Aristotelianism had a profound influence on philosophical and theological thinking in the Islamic and Jewish traditions in the Middle Ages, and it continues to influence Christian theology, especially the scholastic tradition of the Catholic Church. His ethics, though always influential, gained renewed interest with the modern advent of virtue ethics. All aspects of Aristotle's philosophy continue to be the object of active academic study today. Though Aristotle wrote many elegant treatises and dialogues (Cicero described his literary style as "a river of gold"),[2] it is thought that the majority of his writings are now lost and only about one-third of the original works have survived.

Aristotle 

Aristotle is a towering figure in ancient Greek philosophy, making contributions to logic, metaphysics, mathematics, physics, biology, botany, ethics, politics, agriculture, medicine, dance and theatre. He was a student of Plato who in turn studied under Socrates. He was more empirically-minded than Plato or Socrates and is famous for rejecting Plato’s theory of forms.

As a prolific writer and polymath, Aristotle radically transformed most, if not all, areas of knowledge he touched. It is no wonder that Aquinas referred to him simply as “The Philosopher.” In his lifetime, Aristotle wrote as many as 200 treatises, of which only 31 survive. Unfortunately for us, these works are in the form of lecture notes and draft manuscripts never intended for general readership, so they do not demonstrate his reputed polished prose style which attracted many great followers, including the Roman Cicero. Aristotle was the first to classify areas of human knowledge into distinct disciplines such as mathematics, biology, and ethics. Some of these classifications are still used today.

As the father of the field of logic, he was the first to develop a formalized system for reasoning. Aristotle observed that the validity of any argument can be determined by its structure rather than its content. A classic example of a valid argument is his syllogism: All men are mortal; Socrates is a man; therefore, Socrates is mortal. Given the structure of this argument, as long as the premises are true, then the conclusion is also guaranteed to be true. Aristotle’s brand of logic dominated this area of thought until the rise of modern propositional logic and predicate logic 2000 years later.

Aristotle’s emphasis on good reasoning combined with his belief in the scientific method forms the backdrop for most of his work. For example, in his work in ethics and politics, Aristotle identifies the highest good with intellectual virtue; that is, a moral person is one who cultivates certain virtues based on reasoning. And in his work on psychology and the soul, Aristotle distinguishes sense perception from reason, which unifies and interprets the sense perceptions and is the source of all knowledge.

Aristotle famously rejected Plato’s theory of forms, which states that properties such as beauty are abstract universal entities that exist independent of the objects themselves. Instead, he argued that forms are intrinsic to the objects and cannot exist apart from them, and so must be studied in relation to them. However, in discussing art, Aristotle seems to reject this, and instead argues for idealized universal form which artists attempt to capture in their work.

Aristotle was the founder of the Lyceum, a school of learning based in Athens, Greece; and he was an inspiration for the Peripatetics, his followers from the Lyceum.

Logic & History

With the Prior Analytics, Aristotle is credited with the earliest study of formal logic, and his conception of it was the dominant form of Western logic until 19th century advances in mathematical logic. Kant stated in the Critique of Pure Reason that Aristotle's theory of logic completely accounted for the core of deductive inference.

Aristotle "says that 'on the subject of reasoning' he 'had nothing else on an earlier date to speak of'". However, Plato reports that syntax was devised before him, by Prodicus of Ceos, who was concerned by the correct use of words. Logic seems to have emerged from dialectics; the earlier philosophers made frequent use of concepts like reductio ad absurdum in their discussions, but never truly understood the logical implications. Even Plato had difficulties with logic; although he had a reasonable conception of a deductive system, he could never actually construct one and relied instead on his dialectic. Plato believed that deduction would simply follow from premises, hence he focused on maintaining solid premises so that the conclusion would logically follow. Consequently, Plato realized that a method for obtaining conclusions would be most beneficial. He never succeeded in devising such a method, but his best attempt was published in his book Sophist, where he introduced his division method.

Aristotle's scientific method

Like his teacher Plato, Aristotle's philosophy aims at the universal. Aristotle, however, found the universal in particular things, which he called the essence of things, while Plato finds that the universal exists apart from particular things, and is related to them as their prototype or exemplar. For Aristotle, therefore, philosophic method implies the ascent from the study of particular phenomena to the knowledge of essences, while for Plato philosophic method means the descent from a knowledge of universal Forms (or ideas) to a contemplation of particular imitations of these. For Aristotle, "form" still refers to the unconditional basis of phenomena but is "instantiated" in a particular substance (see Universals and particulars, below). In a certain sense, Aristotle's method is both inductive and deductive, while Plato's is essentially deductive from a priori principles.
In Aristotle's terminology, "natural philosophy" is a branch of philosophy examining the phenomena of the natural world, and includes fields that would be regarded today as physics, biology and other natural sciences. In modern times, the scope of philosophy has become limited to more generic or abstract inquiries, such as ethics and metaphysics, in which logic plays a major role. Today's philosophy tends to exclude empirical study of the natural world by means of the scientific method. In contrast, Aristotle's philosophical endeavors encompassed virtually all facets of intellectual inquiry.
In the larger sense of the word, Aristotle makes philosophy coextensive with reasoning, which he also would describe as "science". Note, however, that his use of the term science carries a different meaning than that covered by the term "scientific method". For Aristotle, "all science (dianoia) is either practical, poetical or theoretical" (Metaphysics 1025b25). By practical science, he means ethics and politics; by poetical science, he means the study of poetry and the other fine arts; by theoretical science, he means physics, mathematics and metaphysics.
If logic (or "analytics") is regarded as a study preliminary to philosophy, the divisions of Aristotelian philosophy would consist of: Logic;Theoretical Philosophy, including Metaphysics, Physics and Mathematics;  Practical Philosophy and Poetical Philosophy.
In the period between his two stays in Athens, between his times at the Academy and the Lyceum, Aristotle conducted most of the scientific thinking and research for which he is renowned today. In fact, most of Aristotle's life was devoted to the study of the objects of natural science. Aristotle's metaphysics contains observations on the nature of numbers but he made no original contributions to mathematics. He did, however, perform original research in the natural sciences, e.g., botany, zoology, physics, astronomy, chemistry, meteorology, and several other sciences.
Aristotle's writings on science are largely qualitative, as opposed to quantitative. Beginning in the 16th century, scientists began applying mathematics to the physical sciences, and Aristotle's work in this area was deemed hopelessly inadequate. His failings were largely due to the absence of concepts like mass, velocity, force and temperature. He had a conception of speed and temperature, but no quantitative understanding of them, which was partly due to the absence of basic experimental devices, like clocks and thermometers.

Physics

Motion
Main article: potentiality and actuality
Aristotle defined motion as the actuality of a potentiality as such.Aquinas suggested that the passage be understood literally; that motion can indeed be understood as the active fulfillment of a potential, as a transition toward a potentially possible state. Because actuality and potentiality are normally opposites in Aristotle, other commentators either suggest that the wording which has come down to us is erroneous, or that the addition of the "as such" to the definition is critical to understanding it.[
Causality, The Four Causes
Main article: Four causes
Aristotle suggested that the reason for anything coming about can be attributed to four different types of simultaneously active causal factors:
Material cause describes the material out of which something is composed. Thus the material cause of a table is wood, and the material cause of a car is rubber and steel. It is not about action. It does not mean one domino knocks over another domino.
The formal cause is its form, i.e. the arrangement of that matter. It tells us what a thing is, that any thing is determined by the definition, form, pattern, essence, whole, synthesis or archetype. It embraces the account of causes in terms of fundamental principles or general laws, as the whole (i.e., macrostructure) is the cause of its parts, a relationship known as the whole-part causation. Plainly put the formal cause is the idea existing in the first place as exemplar in the mind of the sculptor, and in the second place as intrinsic, determining cause, embodied in the matter. Formal cause could only refer to the essential quality of causation. A more simple example of the formal cause is the blueprint or plan that one has before making or causing a human made object to exist.
The efficient cause is "the primary source", or that from which the change or the ending of the change first starts. It identifies 'what makes of what is made and what causes change of what is changed' and so suggests all sorts of agents, nonliving or living, acting as the sources of change or movement or rest. Representing the current understanding of causality as the relation of cause and effect, this covers the modern definitions of "cause" as either the agent or agency or particular events or states of affairs. More simply again that which immediately sets the thing in motion. So take the two dominos this time of equal weighting, the first is knocked over causing the second also to fall over. This is effectively efficient cause.
The final cause is its purpose, or that for the sake of which a thing exists or is done, including both purposeful and instrumental actions and activities. The final cause or telos is the purpose or end that something is supposed to serve, or it is that from which and that to which the change is. This also covers modern ideas of mental causation involving such psychological causes as volition, need, motivation or motives, rational, irrational, ethical, and all that gives purpose to behavior.
Additionally, things can be causes of one another, causing each other reciprocally, as hard work causes fitness and vice versa, although not in the same way or function, the one is as the beginning of change, the other as the goal. (Thus Aristotle first suggested a reciprocal or circular causality as a relation of mutual dependence or influence of cause upon effect). Moreover, Aristotle indicated that the same thing can be the cause of contrary effects; its presence and absence may result in different outcomes. Simply it is the goal or purpose that brings about an event (not necessarily a mental goal). Taking our two dominos, it requires someone to intentionally knock the dominos over as they cannot fall themselves.
Aristotle marked two modes of causation: proper (prior) causation and accidental (chance) causation. All causes, proper and incidental, can be spoken as potential or as actual, particular or generic. The same language refers to the effects of causes, so that generic effects assigned to generic causes, particular effects to particular causes, operating causes to actual effects. Essentially, causality does not suggest a temporal relation between the cause and the effect.

Metaphysics

Substance, potentiality and actuality

Aristotle examines the concepts of substance and essence (ousia) in his Metaphysics (Book VII), and he concludes that a particular substance is a combination of both matter and form. As he proceeds to the book VIII, he concludes that the matter of the substance is the substratum or the stuff of which it is composed; e.g., the matter of the house are the bricks, stones, timbers etc., or whatever constitutes the potential house, while the form of the substance is the actual house, namely 'covering for bodies and chattels' or any other differentia (see also predicables). The formula that gives the components is the account of the matter, and the formula that gives the differentia is the account of the form.
With regard to the change (kinesis) and its causes now, as he defines in his Physics and On Generation and Corruption 319b-320a, he distinguishes the coming to be from:
growth and diminution, which is change in quantity;
locomotion, which is change in space; and
alteration, which is change in quality.
The coming to be is a change where nothing persists of which the resultant is a property. In that particular change he introduces the concept of potentiality (dynamis) and actuality (entelecheia) in association with the matter and the form.
Referring to potentiality, this is what a thing is capable of doing, or being acted upon, if the conditions are right and it is not prevented by something else. For example, the seed of a plant in the soil is potentially (dynamei) plant, and if is not prevented by something, it will become a plant. Potentially beings can either 'act' (poiein) or 'be acted upon' (paschein), which can be either innate or learned. For example, the eyes possess the potentiality of sight (innate – being acted upon), while the capability of playing the flute can be possessed by learning (exercise – acting).
Actuality is the fulfillment of the end of the potentiality. Because the end (telos) is the principle of every change, and for the sake of the end exists potentiality, therefore actuality is the end. Referring then to our previous example, we could say that an actuality is when a plant does one of the activities that plants do.
"For that for the sake of which a thing is, is its principle, and the becoming is for the sake of the end; and the actuality is the end, and it is for the sake of this that the potentiality is acquired. For animals do not see in order that they may have sight, but they have sight that they may see."
In summary, the matter used to make a house has potentiality to be a house and both the activity of building and the form of the final house are actualities, which is also a final cause or end. Then Aristotle proceeds and concludes that the actuality is prior to potentiality in formula, in time and in substantiality.
With this definition of the particular substance (i.e., matter and form), Aristotle tries to solve the problem of the unity of the beings, for example, "what is it that makes a man one"? Since, according to Plato there are two Ideas: animal and biped, how then is man a unity? However, according to Aristotle, the potential being (matter) and the actual one (form) are one and the same thing

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