Aristotle Aristotle Lived 384-323 BC. He was a student of Plato. Was the tutor of Alexander the Great. Founded his own school: The Lyceum. He wrote treatises on physics, cosmology, biology, psychology, politics, ethics, language, and logic to name just a few. Was influential well into the 1600s. Was as much a natural scientist has he was a philosopher made detailed observations of plant and animal life and devised detailed theories of change and motion in the physical world. Background Aristotle and Plato Strategy for understanding ancient views about the mind. 1. Metaphysics: their view about the nature of the world. 2. Their understanding of the mind as it is informed by that worldview. 3. Importance to the history of psychology. Aristotle and Plato Recall, Plato thought the universe was divided into two realms: the material world of the senses and the eternal immutable world of the Forms. This was shaped by his study of mathematics and had an impact on his view of the soul (mind). The body belonged to the material world, while the soul belonged to the forms. Aristotle and Plato Aristotle inherited the problem of universals from Plato. Recall, universals are merely the various Forms, which explain the nature of the sensible world. But there is an enormous difficulty with Plato s theory. What do you think it is? 1
Aristotle and Plato The problem is to explain the relationship between the realm of the Forms and material objects. Plato became aware of these difficulties later in his life (the population problem; and the third man argument). Aristotle was also aware of this difficulty and attempted solutions. Aristotle and Plato Aristotle s excursions into botany led him to believe that change and growth in the natural world result from a force in the material objects themselves. Aristotle rejected Plato s theory of the Forms. Instead, he believed universals to be part of the natural world. Aristotle and Plato Aristotle and Plato Aristotle s solution was to replace the idea of two distinct realms with the idea that material things have dual aspects: all objects are a composite of matter and form. In this way universals (Forms) become part of the material objects that make up the material world. In order to better understand this view we need to have an account of Aristotle s notion of substance. Aristotle on Substance Substance refers to the basic elements of the world it is the thing that remains constant throughout the change we see (e.g. the growth of plants and animals; the movement of the stars). Aristotle on Substance There are three different concepts that fall under this term: 1. Substance as matter. 2. Substance as form (or essence). 3. Substance as the combination of 1 & 2. The distinction between matter and form is, roughly, what something is made of and what makes it the kind of thing it is. 2
Marble Matter and Form Bronze Same form different matter. Matter and Form Insofar as they are the same kind of thing, they have the same form. What makes these statues the kind of thing they are is that they portray the same subject the thinker. This is given by the shape of the objects. So the shape is the form. But they are composed of different material (marble and bronze). Matter and Form Matter and Form In this case, both these statues are the same kind of thing they have the same form. But although they both come from bronze, they are different pieces of bronze. The matter is what individuates them its what makes them two distinct objects. Same form different matter. Matter and Form The same holds true of the natural world. Plants and animals of the same species have the same form (or essence) it is what different members of the group have in common. The matter is what differentiates them from one another. But (confusingly) form is also responsible for the uniqueness of each object (e.g. its particular shape). E.g. Your form (or essence) is what makes you a human being but also the unique person you are. Aristotle on Change For Aristotle change was a transformation from potentiality to actuality governed by the laws of causation. For example, an acorn is potentially an oak tree. If the right conditions are met the potential oak tree (found in the acorn) becomes an actual oak tree. 3
Aristotle on Change 4 Causes Potentiality 1. Material cause: the material that makes up the object (e.g. marble). 2. Efficient cause: the agent of change or the means by which change is induced (e.g. the sculptor). 3. Formal cause: the expression of what an object is (e.g. the shape of the statue). 4. Final cause: the end or purpose for a thing why it is done (the idea of the statue in the sculptor s mind; as a tribute to thinking). Actuality Aristotle on Change In living things the principle of change is within the object itself. For example, an acorn wants to become an oak tree. The Definition of the Soul 1. Natural bodies (e.g. rocks, trees, water, animals ) are substances in the sense of composites of form and matter. 2. Some natural bodies are living, and some are not. 3. Because a living body is a body of a particular kind (living!), the body cannot be the soul. E.g. the difference between a living body and a dead one is that one possesses a soul. Thus, the body (tissue, bone etc.) cannot be the soul. The body is merely what makes life possible. The soul is a substance a fundamental element of the world. Thus, it must be either matter, form or a combination. All living things are composites of matter and form. So the soul must be one or the other. But it can t be matter because matter is only potentially a living thing. Soul must be a substance in the sense of the form of a natural body having life potentially within it. The difference between a body that is potentially alive and one that is actually alive is the presence of a soul. 4
Soul as the Form of Living Things In living things the form is what makes a plant or animal a member of one species or another. An acorn becomes an oak tree because it has the form or soul of an oak. Same species = same soul. Since soul can only enliven matter with a particular kind of organization (having the right parts for living), the soul is the actuality of a natural organized body. But the soul is more than just a principle of life. It is also responsible for the naturally organized body functioning in the way that it does. In the natural world, what makes something the kind of thing it is (its form) is a principle of growth and movement within the thing itself. Life is growth and movement. It is the specific nature of this power that determines the species to which something belongs. Things belong to a species in virtue of what they do rather than how they look. E.g. there are certain activities that are natural for dogs. It is the capacity for this kind of activity that makes something a dog. Physical organization of the dog make this activity possible, but the soul is what makes this possibility actual. Consider an axe (Aristotle s example). If it were a natural thing, its soul would be what makes it an axe. This would be its ability to cut wood. But an axe is not a natural thing, for if it were, it would be able to cut wood by itself. Living things have the power in themselves to do the kind of things that make them the thing they are (e.g. growth, reproduction, perception ) Consider an eye. If an eye were a living thing, sight would be its soul, since that s what makes it what it is. Eyes of living creatures see, in contrast to the eyes of statues. Similarly, the power of sense (sensibility) is what gives form to the sensible organs of the body. Thus, the soul of a living thing is like a hierarchy of forms, each contributing to the powers/abilities that constitute life for that species. 5
What we get here is functional account of the mind. The mind (or soul) is understood in part by how it makes actual the functioning of a living thing. Unlike Plato, Aristotle believed the soul was inseparable from the body it would be like asking whether the wax and its shape are one. Faculties of the Soul For Aristotle the various species form a hierarchy according to the nature of their activities. All grow and reproduce. But not all forms of life possess sensory organs to perceive the world around them. This led him to propose different faculties of the soul whereby a species is categorized in accordance with the faculties they possess. Faculties of the Soul 1. Nutritive Soul: all living things have the power to feed and reproduce. 2. Sensitive Soul: some also have the powers of locomotion and perception. 3. Rational Soul: only human beings have the power reason and reflection. All three are present in humans. Aristotle on Perception Vision For Aristotle colour is what lies on the surface of visible objects. We see other things through a transparent medium/substance that exists between our eyes and the surface of coloured objects. It is not visible, but is to be found in, e.g., air and water. Aristotle on Perception For Aristotle, colour is, by definition something that changes this transparent substance. And as a result of this change things are made visible to the eye. This transparent substance is either active or inactive only when it is active is colour visible through it. Light is the active state of this substance and darkness is the inactive state. Aristotle on Perception Fire excites the activity of this substance (efficient cause), which is why we can see in the presence of candle-light, sunlight etc. Fire produces light (in Aristotle s terms). This now active substance in water or air (and the eye) can then transmit the colour from the surface of the object to the soul through the eye. The soul literally takes on the colours of the things we see around us. 6
The Passive Intellect Thinking Aristotle considers thinking to be in part a passive enterprise, somewhat like sense perception. The difference between it and sense perception lies simply in what is perceived. Each sense is responsible for our awareness of the particular qualities for which it is designed to sense (the proper sensibles). Each quality acts on the sense organ in a way to reproduce that quality (literally) in the soul. The Passive Intellect Thinking then is the process by which the soul acted upon by those things which are capable of being thought. In thinking the soul takes on the nature of what it is thinking about. What is capable of being thought about? The form (or essence) of the object. The Passive Intellect The soul literally takes on the form of the objects it is thinking about passively. The Passive Intellect Recall form is what makes an object the kind of thing it is (essence). Imagine perceiving a galloping horse. We perceive it with our five senses But how do we know it s a horse (i.e. its horseness)? We seem to take this for granted. There must be a faculty by which we perceive the essences of things. The Passive Intellect Its like the way in which warm wax receives a seal. Just as the warm wax can receive any impression the mind can think about any essence take on any form. As a result, Aristotle thought the mind did not have any essence of its own. E.g. eyes have there own nature to become coloured this is why they can only perceive colours. The Active Intellect Aristotle also though there was more to the mind merely passively taking on forms. Recall the statue. For it to exist there must be material and something that causes the material to become a statue. In vision the analogue of matter is the faculty of sight in the soul, which is potentially coloured. The cause of vision (taking on colour by the soul) is fire. 7
The Active Intellect The soul is the matter of thought its potential to take on different forms. But there must be an active cause to bring that about (like fire in vision). But in this case there is no external cause the mind is its own cause of thinking. Thus, there must be an active mind that is the cause of thinking. This accounts for the sense in which thought is a kind of activity. The active intellect appears to be immortal since it is separate from the body controversial. Aristotle on Memory Memory for Aristotle was the recall of events that have passed perception is of the present. He presented the first associationist theory of memory. Associationism: the doctrine that ideas follow from one another in memory if they were experienced in relation to one another. Aristotle on Memory Remembering for Aristotle, was the process of following a chain of associated ideas to arrive at the thing we want to recall. For Aristotle, associations are produced by means of the law of association: similarity, contrast, and contiguity. This idea still has force in modern psychology (e.g. in behaviourism; protype theory ). Aristotle on Memory The laws of association 1. Similarity: we tend to be reminded of something to the extent that it resembles what we are currently experiencing (e.g. Aristotle Plato). 2. Contrast: sometimes we are reminded of something to the extent that it means the opposite of what we are currently experiencing (e.g. black white). 3. Contiguity: we will tend to be reminded of things that were previously experienced with what we are currently experiencing (e.g. salt pepper). Aristotle on Memory Memory vs. recollection. Other animals have memory which is a kind of elementary matching of current sensations to previous experiences (episodic memory?). It s a kind of simple recall. Only humans have recollection which is an of inferential process. We don t simply recall the past we have to infer it on the basis of our current experience (reconstructive). Aristotle Summary Aristotle continues a line of thinking that begins with Pythagoras and is developed and changed in Plato. The problem of universals motivated Aristotle s own view. The soul was (i) the source of life; and (ii) the seat of the intellect. For Plato the soul is part of the Forms, but for Aristotle the soul is part of the natural world of material objects and living things. 8
Aristotle Summary According to this new view, the principles by which the soul operates are, in general, the same as those that govern the change and movement in other natural objects (e.g. rocks, trees ). Even though there is some mention of the eternal nature of the active intellect the operation of the intellect follows the same pattern as that of sensory perception and organic activity in general. Aristotle Summary In making the mind part of the natural world, Aristotle offers us the first great naturalist theory almost all modern psychologists are naturalists. The natural world (as opposed to the Forms) is the true object of study. His theory of sensory perception suggests that perception gives us a direct and reliable link to the world. Aristotle Summary Thus, our senses (observation!) provides the best means of trying to understand the world. In this way, Aristotle is also the first great empiricist/scientist giving rise to what would become the cornerstone of modern science. This is the first big move away from rationalism. His laws of causation provide the foundation for later scientific thinking influential well into medieval times. Aristotle Summary As in Plato we get A theory of learning. A theory of memory. A theory of cognition. Anticipation of the nature/nurture debate movement towards the nurture side. Teleological explanation is the beginning of a kind of psychological explanation things done for reasons/purposes. Thomas Aquinas Thomas Aquinas Lived 1225-1274AD. The Catholic church came to prominence around 500AD 1500AD. Christianity was the dominant religion. Aquinas was one of the greatest interpreters of Aristotle s work. He showed that Aristotle s views could be reconciled with Christianity. 9
Thomas Aquinas For example, Aquinas s 5 ways (arguments for the existence of God) were developed on the basis of Aristotle s model of causation. E.g. The argument from Motion. 1) Nothing can move itself. 2) If every object in motion had a mover, then the first object in motion needed a mover. 3) This first mover is the Unmoved Mover, called God. This also made use of Aristotle s cosmology and it s dependence on the Prime Mover. Thomas Aquinas The Scala Natura The Great Chain of Being. In Aristotle we see a division amongst the animals by way of the kind of soul they possess nutritive, sensitive, rational. This is a hierarchical ordering. The Scala Natura The Great Chain of Being Pure Actuality (Prime Mover) Humans (Rational) Animals (Sensitive) Plants (Nutritive) Non-living natural objects (e.g. rocks, bone..) The elements (earth, air, fire, water) Pure substance/pure Potentiality The Scala Natura The Great Chain of Being For Aquinas, things were ordered in the world according to their perfection and reflecting God s plan. Humans are close to the top of the chain of being, with God at the very top. Everything has a purpose (teleology) God is the Final Cause of all in the world. The Great Chain of Being reflects God s plan. Thus, the Aristotelian world-view is consistent with Christianity. The Scala Natura The Great Chain of Being This had an important influence on Taxonomy in biology e.g. the Three Kingdoms (animal, vegetable and mineral) that made up Linnaeus s taxonomic system). The idea was still influential on Shakespeare and up to 1667 Milton s Paradise Lost. In fact, it is still present in some versions of Christianity today that God has a purpose for all things a master plan. 10
The Scientific Revolution Nicolas Copernicus (1473-1543) Nicolas Copernicus Up until Copernicus publication of On the Revolutions of the Heavenly Bodies, the Ptolemaic (90-168AD) model of the universe was dominant theory. Ptolemy s model was a detailed mathematical account of the orbits of the planets that was geocentric (earth at the center). Aristotle also had a geocentric cosmology. Nicolas Copernicus Copernicus revolutionized the way we viewed the planetary system by proposing that the sun was the center of the (known) universe heliocentric model of the universe. This upset a great deal of traditional thinking. Cosmology was tied to the notion of the Great Chain of Being. Nicolas Copernicus Francis Bacon (1561-1626) The Earth was the focus of God s creation an as such was held to be the center universe God s plan. As such his view was rejected by the Church. But it inaugurated an enormous shift in our thinking about the world. 11
Francis Bacon Bacon ushered in a new way of thinking about how we ought to go about understanding the world. It was the first articulation of the scientific method in his Novum Organon a play on Aristotle s Organon. Bacon was deeply critical of the ancients and challenged the fundamental form of reasoning they used in the acquisition of knowledge the deductive method. He argued that there had been little progress to our understanding of the world and that a reform was required. Francis Bacon In the place of deduction, he argued for an inductive method of inquiry. Scientific reasoning is still held to be a form of inductive reasoning. The goal was, through experience, to collect facts in an unbiased way. Then on the basis of an analysis of these facts we proceed to make modest generalizations about the nature of the world inductive generalizations! Francis Bacon In outline, this is an articulation of the basic tenets of the scientific method observation, experimentation and generalization. Next Class Galileo, Descartes, Newton and the British Empiricists. 12