Plato
Someone once said that the rest of philosophy after Plato is merely a footnote to his. There is no question as to the significance of Plato to the rest of philosophy since many of the questions we now consider were first dealt with systematically by Plato. This is not to say that Plato was the first to ask such questions; far from it. In fact, by the time Plato arrived on the scene philosophy was already a fairly developed field with many advocates of many diverse positions. What Plato did was to offer an attempt to systematically answer the various questions then being asked.
Besides his insights in philosophy, Plato's other major contribution is to give us some knowledge of his teacher, Socrates, whom himself did not write anything. Socrates was interested in knowledge as a way to guide one's life. In his view to know the Good was to do the Good, so obviously, knowledge was very important. Plato's theory begins as an attempt to answer the question of the origin of knowledge; a question of epistemology. In answering this question Plato not only formulates a theory of knowledge but also a metaphysical theory. Before considering the theory itself we should spend some time providing a context for it. Without this context, Plato's theory is likely to seem very strange.
As mentioned above, Plato is working within the framework of Socrates' ideas about knowledge. Socrates was a major inspiration for Plato's theory. Socrates believed that the important thing in philosophy was to arrive at clear concepts. To understand a concept, we need to arrive at its true definition, what Socrates called the essence of the concept. In the dialogue titled "Euthyphro," Socrates illustrates his method by attempting to answer the question "What is piety?" While failing to come to a definite answer the dialogue illustrates the method Socrates became famous for. He would profess ignorance of a subject and attempt to elicit from his dialogue partner an adequate answer to the question at hand. The process can be outlined in six steps:
1. Arrive at a statement of the definition of a concept.
2. Try to find examples that would show the original statement is false (this is very important in theorizing; what this step illustrates is the need to search for evidence against one's theory to take account of it).
3. If any exceptions are found the original definition must be false or at least imprecise.
4. The definition should then be reformulated.
5. Again we should attempt to find exceptions and continue refining the definition.
6. What we arrive at after repeated attempts is a precise definition of the concept in question.
The result of this method is a much deeper understanding of the concept whether it be piety, truth, justice, good, or whatever.
What fascinated Socrates was our ability to think in terms of abstract ideas. We can observe individual human beings but can think of the general concept of the human being as well. The insight that Plato drew from this and the Socratic method was the idea that concepts have reality. This may seem very strange to say but in Plato's view if a concept can be defined it must have a real existence. What kind of existence do ideas (concepts) have? We will address this below. The important thing here is that if something can be thought it must be real. Concepts are not just imaginary creations of the human mind. These concepts which are the source of knowledge have a real separate existence.
Socrates was not the only philosopher Plato learned from. In particular, Plato was inspired by two philosophers with whom he disagreed. One of the most prominent Sophists (wise men who would teach for a fee) of the day was Protagoras. Like many of the Sophists, he was a relativist. He believed that each individual decides for himself what is true and what is false. He once said "man is the measure of all things," meaning that each person decides for himself what truth is. For Plato, this was completely unworkable as a theory of knowledge. If knowledge were relative and up to each individual to decide upon, then knowledge would be impossible. Consider for example mathematics. Suppose that knowledge was relative. Perhaps for me, 2+3=7 is true. You would probably disagree with this but then that would just be your opinion. Now, if this were the case would knowledge of mathematics be possible? Of course not! From this Plato deduces that knowledge must be objective. That is, it must be separate from individual opinion. Remember that!
A second philosopher with whom Plato disagreed was Heraclitus. Greek philosophers were very interested in change and his theory of change was very popular at the time. In a very common-sense fashion, he observed that everything changes; everything is in a constant state of flux. "You can't step into the same river twice." Again for Plato, this idea led to impossible conclusions. Knowledge must be about what is, not what is not. That is knowledge must be something we can define (remember Socrates?). Suppose everything is in a constant state of flux. That must mean that our knowledge is in a constant state of flux as well with nothing remaining the same. So again, to use a mathematical example 2+3=5 might be true today but since knowledge constantly changes, 2+3=7 tomorrow! Clearly for knowledge to be possible some things must be unchanging. Plato did not want to say that everything is unchanging. Heraclitus is on to something with his observation of change. However, for Plato, knowledge cannot be connected to things that change, otherwise, knowledge would be impossible.
OK, so where are we. Plato's line of reasoning can be summed up as follows:
1. Knowledge is possible. We do know so this is not in dispute.
2. Knowledge must be "of something." Plato picked up this little idea from Parmenides a philosopher who preceded Socrates (Socrates himself probably got the idea of essence partially from Parmenides!)
3. The "something" knowledge must be connected to has to be objective (remember the problems with Protagoras' view?)
4. The "something" knowledge must be connected to cannot be changing (remember Heraclitus?)
So where do we go from here? We need to learn more about this "something" that knowledge is connected to since this is the source of our knowledge. We know it must be objective and unchanging. Question: Are there any objects in this world that are BOTH objective and unchanging? For Plato, the answer to this question was no. I mean, just look around, you can't find any unchanging objects. So from this Plato deduced that the source of knowledge must be separate from this world. There must be another world! A transcendent world to be precise. By transcendent we mean separate from space and time. If you think this is a little strange, just pause to consider whether you believe in a heaven or something after this life. If you do then you already believe in a transcendent world so Plato's idea should not be all that foreign to you.
OK. So we know that the source of our knowledge is transcendent which means it is not subject to space and time and we know that the source of our knowledge is unchanging. This must mean that these objects are eternal; that is they have no beginning or end. Why? Because coming into being and going out of existence are both forms of change and these objects do not change. But how do we know about them if they aren't here in this world?
These are not run-of-the-mill everyday objects we are dealing with here. For one thing, we can't sense them. So our knowledge of them doesn't come from sense experience. But remember, we do know. So how do we explain that? It must be the case, says Plato, that our knowledge of these objects is intelligible; that is we learn about them through the intellect, not our senses.
A central image that Plato uses to describe his metaphysics and epistemology is the divided line. What this illustrates is that there are different levels of knowledge and reality. If you imagine a vertical line divided into two unequal halves (the bottom half is smaller to reflect the lesser reality and knowledge) the realm below the dividing line is the realm of becoming while the realm above is the realm of Being. From an epistemology perspective, the bottom half is opinion while the top half is knowledge.
The metaphysics side is represented on the left while the epistemology is represented on the right. By mathematical forms, Plato means things like the triangle or any other perfect geometrical figure. What we illustrate when we draw a triangle is only an imperfect representation of what we conceive of as the perfect triangle. At the top of the line are the true objects of knowledge. These objective, unchanging, transcendent, eternal, intelligible objects Plato called the Forms. They are the source of all our knowledge and more than that they are the source for everything that exists. To understand the forms better we can address several questions the answers to some of which may already be clear.
1. What are the Forms? Forms for Plato are the most real objects that exist. They function as patterns for the objects and concepts that we know of in this world. For instance, we can know Justice but this knowledge does not come from particular examples of justice that we observe. Rather, the Form of Justice is what allows us to identify particular instances of justice here. The same goes for objects as well. We can observe individual instances of chairs, human beings, trees, etc. But our knowledge of these things, and their very existence, comes from their respective Forms. In this respect, Plato often refers to the Forms as a model (or pattern) for objects.
2. How do Forms interact with objects? Plato also says that the Form causes the object to exist. Objects, on the other hand, participate in the Forms. So the origin of our knowledge comes from the Forms, but more importantly, the origin of things themselves comes from the Forms. While each class of objects participates in its Form, Plato is not exactly clear as to how detailed this schema is. He does say that there are no forms for every individual object but it is unclear, for example, whether there are forms not only for each type of animal (dog, cat, fish) but also for each species or breed (of dog, or cat or whatever). The important point is that the Form is the cause and the object is the effector in the case of concepts, the Form is the cause of our concept (of justice, piety, beauty) and the concept is the effect.
3. How do Forms interact with each other? This gets a little complicated and again, Plato never adequately fills in the details of the theory. But it is clear that just as our concepts exist in a hierarchy so do the Forms. For example, there is a Form for Chair and a Form for Desk. But chairs and desks are types of furniture so there is also a Form Furniture. The hierarchy extends all the way up to higher Forms (such as mathematical forms and abstract concepts. The highest Form is the Form of the Good.
4. Where are the Forms? As we illustrated above, Plato deduces that the Forms are transcendent. So the Forms are definitely not in this world of space and time. The question of where is difficult for Forms since they do not occupy space. Plato does allude from time to time to an eternal realm of Forms but the details of this are necessarily scant. It’s kind of like asking "Where is heaven?" It may not be a place in the conventional sense of the term.
So how do we gain knowledge of the forms? Well, we've said that the Forms are intelligible which means we can only learn of them through the intellect. But for Plato, it is somewhat incorrect to say we learn of them (at least in the ordinary sense of that word). Part of Plato's theory is that the soul is immortal; it not only survives the death of the body it preceded the birth of the body as well. Given this, Plato says that the soul was in contact with the Forms prior to birth. So our knowledge is innate. For Plato, this means ALL knowledge. Learning, then, is recollection. Granted, it takes sense experience to trigger the recollection but the knowledge itself does not come from the sense experience. How could it? Sense experience only gives us information about things that are constantly changing and knowledge, as we have shown, cannot be connected to things that are in constant flux.
Plato's theory may sound very alien to our ears. He asks us to believe things we may find hard to believe; especially in the absence of concrete evidence. While it is true that Plato does not offer us concrete evidence this does not necessarily mean his theory is flawed. In epistemology, Plato is a rationalist which is a term that means that knowledge comes from reason, not sense experience. So it would not seem appropriate to Plato to offer us sense experience as evidence for his theory. Plato's approach is to deduce his conclusions from rational principles. Still, Plato did have his critics. Not everyone agreed with his theory. One particularly eloquent opponent was one of Plato's best students named Aristotle. It is to the philosophy of Aristotle that we turn next.
Besides his insights in philosophy, Plato's other major contribution is to give us some knowledge of his teacher, Socrates, whom himself did not write anything. Socrates was interested in knowledge as a way to guide one's life. In his view to know the Good was to do the Good, so obviously, knowledge was very important. Plato's theory begins as an attempt to answer the question of the origin of knowledge; a question of epistemology. In answering this question Plato not only formulates a theory of knowledge but also a metaphysical theory. Before considering the theory itself we should spend some time providing a context for it. Without this context, Plato's theory is likely to seem very strange.
As mentioned above, Plato is working within the framework of Socrates' ideas about knowledge. Socrates was a major inspiration for Plato's theory. Socrates believed that the important thing in philosophy was to arrive at clear concepts. To understand a concept, we need to arrive at its true definition, what Socrates called the essence of the concept. In the dialogue titled "Euthyphro," Socrates illustrates his method by attempting to answer the question "What is piety?" While failing to come to a definite answer the dialogue illustrates the method Socrates became famous for. He would profess ignorance of a subject and attempt to elicit from his dialogue partner an adequate answer to the question at hand. The process can be outlined in six steps:
1. Arrive at a statement of the definition of a concept.
2. Try to find examples that would show the original statement is false (this is very important in theorizing; what this step illustrates is the need to search for evidence against one's theory to take account of it).
3. If any exceptions are found the original definition must be false or at least imprecise.
4. The definition should then be reformulated.
5. Again we should attempt to find exceptions and continue refining the definition.
6. What we arrive at after repeated attempts is a precise definition of the concept in question.
The result of this method is a much deeper understanding of the concept whether it be piety, truth, justice, good, or whatever.
What fascinated Socrates was our ability to think in terms of abstract ideas. We can observe individual human beings but can think of the general concept of the human being as well. The insight that Plato drew from this and the Socratic method was the idea that concepts have reality. This may seem very strange to say but in Plato's view if a concept can be defined it must have a real existence. What kind of existence do ideas (concepts) have? We will address this below. The important thing here is that if something can be thought it must be real. Concepts are not just imaginary creations of the human mind. These concepts which are the source of knowledge have a real separate existence.
Socrates was not the only philosopher Plato learned from. In particular, Plato was inspired by two philosophers with whom he disagreed. One of the most prominent Sophists (wise men who would teach for a fee) of the day was Protagoras. Like many of the Sophists, he was a relativist. He believed that each individual decides for himself what is true and what is false. He once said "man is the measure of all things," meaning that each person decides for himself what truth is. For Plato, this was completely unworkable as a theory of knowledge. If knowledge were relative and up to each individual to decide upon, then knowledge would be impossible. Consider for example mathematics. Suppose that knowledge was relative. Perhaps for me, 2+3=7 is true. You would probably disagree with this but then that would just be your opinion. Now, if this were the case would knowledge of mathematics be possible? Of course not! From this Plato deduces that knowledge must be objective. That is, it must be separate from individual opinion. Remember that!
A second philosopher with whom Plato disagreed was Heraclitus. Greek philosophers were very interested in change and his theory of change was very popular at the time. In a very common-sense fashion, he observed that everything changes; everything is in a constant state of flux. "You can't step into the same river twice." Again for Plato, this idea led to impossible conclusions. Knowledge must be about what is, not what is not. That is knowledge must be something we can define (remember Socrates?). Suppose everything is in a constant state of flux. That must mean that our knowledge is in a constant state of flux as well with nothing remaining the same. So again, to use a mathematical example 2+3=5 might be true today but since knowledge constantly changes, 2+3=7 tomorrow! Clearly for knowledge to be possible some things must be unchanging. Plato did not want to say that everything is unchanging. Heraclitus is on to something with his observation of change. However, for Plato, knowledge cannot be connected to things that change, otherwise, knowledge would be impossible.
OK, so where are we. Plato's line of reasoning can be summed up as follows:
1. Knowledge is possible. We do know so this is not in dispute.
2. Knowledge must be "of something." Plato picked up this little idea from Parmenides a philosopher who preceded Socrates (Socrates himself probably got the idea of essence partially from Parmenides!)
3. The "something" knowledge must be connected to has to be objective (remember the problems with Protagoras' view?)
4. The "something" knowledge must be connected to cannot be changing (remember Heraclitus?)
So where do we go from here? We need to learn more about this "something" that knowledge is connected to since this is the source of our knowledge. We know it must be objective and unchanging. Question: Are there any objects in this world that are BOTH objective and unchanging? For Plato, the answer to this question was no. I mean, just look around, you can't find any unchanging objects. So from this Plato deduced that the source of knowledge must be separate from this world. There must be another world! A transcendent world to be precise. By transcendent we mean separate from space and time. If you think this is a little strange, just pause to consider whether you believe in a heaven or something after this life. If you do then you already believe in a transcendent world so Plato's idea should not be all that foreign to you.
OK. So we know that the source of our knowledge is transcendent which means it is not subject to space and time and we know that the source of our knowledge is unchanging. This must mean that these objects are eternal; that is they have no beginning or end. Why? Because coming into being and going out of existence are both forms of change and these objects do not change. But how do we know about them if they aren't here in this world?
These are not run-of-the-mill everyday objects we are dealing with here. For one thing, we can't sense them. So our knowledge of them doesn't come from sense experience. But remember, we do know. So how do we explain that? It must be the case, says Plato, that our knowledge of these objects is intelligible; that is we learn about them through the intellect, not our senses.
A central image that Plato uses to describe his metaphysics and epistemology is the divided line. What this illustrates is that there are different levels of knowledge and reality. If you imagine a vertical line divided into two unequal halves (the bottom half is smaller to reflect the lesser reality and knowledge) the realm below the dividing line is the realm of becoming while the realm above is the realm of Being. From an epistemology perspective, the bottom half is opinion while the top half is knowledge.
The metaphysics side is represented on the left while the epistemology is represented on the right. By mathematical forms, Plato means things like the triangle or any other perfect geometrical figure. What we illustrate when we draw a triangle is only an imperfect representation of what we conceive of as the perfect triangle. At the top of the line are the true objects of knowledge. These objective, unchanging, transcendent, eternal, intelligible objects Plato called the Forms. They are the source of all our knowledge and more than that they are the source for everything that exists. To understand the forms better we can address several questions the answers to some of which may already be clear.
1. What are the Forms? Forms for Plato are the most real objects that exist. They function as patterns for the objects and concepts that we know of in this world. For instance, we can know Justice but this knowledge does not come from particular examples of justice that we observe. Rather, the Form of Justice is what allows us to identify particular instances of justice here. The same goes for objects as well. We can observe individual instances of chairs, human beings, trees, etc. But our knowledge of these things, and their very existence, comes from their respective Forms. In this respect, Plato often refers to the Forms as a model (or pattern) for objects.
2. How do Forms interact with objects? Plato also says that the Form causes the object to exist. Objects, on the other hand, participate in the Forms. So the origin of our knowledge comes from the Forms, but more importantly, the origin of things themselves comes from the Forms. While each class of objects participates in its Form, Plato is not exactly clear as to how detailed this schema is. He does say that there are no forms for every individual object but it is unclear, for example, whether there are forms not only for each type of animal (dog, cat, fish) but also for each species or breed (of dog, or cat or whatever). The important point is that the Form is the cause and the object is the effector in the case of concepts, the Form is the cause of our concept (of justice, piety, beauty) and the concept is the effect.
3. How do Forms interact with each other? This gets a little complicated and again, Plato never adequately fills in the details of the theory. But it is clear that just as our concepts exist in a hierarchy so do the Forms. For example, there is a Form for Chair and a Form for Desk. But chairs and desks are types of furniture so there is also a Form Furniture. The hierarchy extends all the way up to higher Forms (such as mathematical forms and abstract concepts. The highest Form is the Form of the Good.
4. Where are the Forms? As we illustrated above, Plato deduces that the Forms are transcendent. So the Forms are definitely not in this world of space and time. The question of where is difficult for Forms since they do not occupy space. Plato does allude from time to time to an eternal realm of Forms but the details of this are necessarily scant. It’s kind of like asking "Where is heaven?" It may not be a place in the conventional sense of the term.
So how do we gain knowledge of the forms? Well, we've said that the Forms are intelligible which means we can only learn of them through the intellect. But for Plato, it is somewhat incorrect to say we learn of them (at least in the ordinary sense of that word). Part of Plato's theory is that the soul is immortal; it not only survives the death of the body it preceded the birth of the body as well. Given this, Plato says that the soul was in contact with the Forms prior to birth. So our knowledge is innate. For Plato, this means ALL knowledge. Learning, then, is recollection. Granted, it takes sense experience to trigger the recollection but the knowledge itself does not come from the sense experience. How could it? Sense experience only gives us information about things that are constantly changing and knowledge, as we have shown, cannot be connected to things that are in constant flux.
Plato's theory may sound very alien to our ears. He asks us to believe things we may find hard to believe; especially in the absence of concrete evidence. While it is true that Plato does not offer us concrete evidence this does not necessarily mean his theory is flawed. In epistemology, Plato is a rationalist which is a term that means that knowledge comes from reason, not sense experience. So it would not seem appropriate to Plato to offer us sense experience as evidence for his theory. Plato's approach is to deduce his conclusions from rational principles. Still, Plato did have his critics. Not everyone agreed with his theory. One particularly eloquent opponent was one of Plato's best students named Aristotle. It is to the philosophy of Aristotle that we turn next.