WHEN ARISTOTLE’S NAME is turned into an adjective to modify a noun, it is usually attached to the word “logic.” We say of an argument we have just listened to, “That’s Aristotelian logic,” sometimes intending to praise, sometimes to disparage.
So, when Plato’s name is turned into an adjective, it is usually attached either to “love” or to “idea.” We speak of a certain type of friendship as platonic love; or we say, “That’s only a Platonic idea and it has nothing to do with reality.”
What underlies the derogatory thrust of the phrase “Platonic idea” is, of course, Plato’s theory of ideas, which is hardly a commonsense doctrine that most people readily embrace. On the contrary, when they understand it, they find it runs counter to their commonsense view of the way things are. But it is far from being wholly wrong. Of the two central tenets of Plato’s theory of ideas, one was right and the other wrong.
Let us begin with what was wrong about it. For Plato, there were two worlds, not one—the sensible world of changing physical things that we apprehend by means of our senses and the world of intelligible objects that we apprehend by means of our intellects or minds. For him, both are real worlds, where calling them “real” means that they exist independently of our apprehending them.
Even if neither men nor other animals that have eyes or ears or other senses existed, the world of sensible things would exist exactly as it is. So, too, for Plato, even if there were no human beings with the characteristic human ability to think of such objects as truth and goodness, or justice and liberty, these objects would exist—exist independently of all thinking minds. That is why in Plato’s view, the idea of the good or the idea of justice has a full measure of reality.
Plato went further. More than a full measure of reality, the world of ideas had for him a superior grade of reality. The physical things that we perceive through our senses come into being and pass away and they are continually in flux, changing in one way or another. They have no permanence. But though we may change our minds about the ideas we think about, they themselves are not subject to change. Unlike living organisms, they are not born and do not die. Unlike stars and atoms, they do not move about in space. Unlike the familiar physical objects that surround us, they do not get hot or cold, larger or smaller, and so on.
The world of changing physical things is thus for Plato a mere shadow of the much more real world of ideas. When we pass from the realm of sense experience to the realm of thought, we ascend to a higher reality, for we have turned from things that have no enduring existence to enduring and unchanging (Plato would say “eternal”) objects of thought—ideas.
For those of us who cannot shuck off our commitment to common sense, Plato goes too far in attributing reality to ideas, and much too far in exalting their reality over the reality of sensible phenomena—the reality of the ever-changing world we experience through our senses. We do not hesitate to reject Plato’s theory of ideas, and declare him wrong in attributing reality to ideas as well as to physical things, and a superior reality at that. For us commonsense fellows, it is the world of ideas that is comparatively shadowy as compared with the tangible, visible, audible world of things that press on us from all sides.
However, we, too, would be going too far if we regarded ideas as having no existence at all, or regarded them as existing only in our minds when we are thinking. That would make them entirely subjective, as subjective as the feeling of pain you experience when a finger is squeezed too hard, or as subjective as the toothache you have that you can tell me about but that I cannot experience because at the moment it is yours and yours alone.
Plato was right, not wrong, in holding that ideas are objects that the human mind can think about. He was right in insisting on their objectivity. This, understood in the simplest manner possible, amounts to saying that you and I can engage in conversation about one and the same idea because it is an object that you and I are thinking about, just as you and I can engage in conversation about one and the same overcoat when you help me put it on and ask me whether it is warm enough. When you and I discuss truth or justice, the idea of truth or justice is before our minds, or present to our minds, just as much as the overcoat that you help me on with is handled by both of us at the same time.
If anyone has difficulty in understanding this, it is because the word “idea” has two meanings, not one—one in which it is used to refer to something that is entirely subjective and one in which it is used to refer to something that is quite objective.
In the first meaning, the word has been used to refer to the whole range of entities that comprise the ideational content of our consciousness. In this broad sense of the word, it covers the sensations and perceptions we have, the images we form, the memories we summon up, and the conceptions or notions that we employ in our thinking.
When the word “idea” is used in this way by psychologists, all the various items referred to are certainly subjective. My sensations or perceptions are not yours; the images that occur in my dreams or the memories I dwell upon when I reminisce are mine alone; so, too, are the concepts or notions I have been at some pains to form as I study a difficult science.
To call them all “subjective” is simply to say that they are private, not public. When I speak of them as mine—my perception, my memory, or my concept—I am saying that the perception, memory, or concept in question belongs to me and me alone. You can have no access to it, just as you cannot have access to the toothache I am suffering.
In its other meaning, the word “idea” refers to an object that two or more persons can have access to, can focus on, can think about, can discuss. While this meaning may not be as familiar, neither is it entirely strange or puzzling.
If we disagree about a decision just handed down by the Supreme Court, we may find ourselves challenging each other’s views about justice. If I ask you for your view of justice, I am asking you to tell me what you think about it, and I am also prepared to tell you what I think about it. The “it” here is justice as an object of thought, both your thought and mine, not justice as a concept in your mind, but not mine.
This is not to deny that you and I have concepts in our minds—concepts we think with when we think about justice. Furthermore, your concepts and mine are distinct. But that does not prevent both of us from thinking about one and the same object—an object of thought we call “justice,” and sometimes refer to as “the idea of justice.”
This runs parallel to saying that the quite distinct percepts you and I have are what enable us to perceive when we do perceive one and the same perceptible object. Even though I use my percept and you use yours, as means or instrumentalities for perceiving a sensible object, the sensible object that we both perceive (such as the overcoat you help me put on) remains one and the same. So, too, you have your memory and I have mine of a football game we both attended, but we can both remember one and the same forward pass that won a victory in the last minute of play.
Let me illustrate the point I am trying to make by harking back for a moment to the book I wrote about the idea of freedom. Because it attempted to examine the whole range of Western thought about freedom, it considered what has been written about that subject by hundreds of authors. Some of them by the way, used the word “freedom,” and some used “liberty,” but it was always perfectly clear that these were merely two words for the same object of thought.
However, it was not so clear that all of the authors who wrote about the subject, using either the word “freedom” or the word “liberty,” were talking about one and the same object. Some, for example, concentrated wholly on the freedom persons enjoy when they can act as they please. This is the liberty of which a person in chains or in prison is deprived. Some were concerned with the freedom of the will—the freedom of choice that those who call themselves determinists deny.
The idea of freedom—or, what amounts to the same thing, freedom as an object of thought—includes both of the freedoms mentioned. When some authors write about freedom, they concentrate on one aspect of it, not another. But all the authors who concentrate on that one aspect of freedom are engaged in thinking about the same object. If that were not the case, it would be meaningless to say that they were in agreement or disagreement about it.
For example, thinking about freedom as consisting in being able to act as one pleases, certain authors hold it sufficient for such liberty to consist in exemption from physical coercion or duress. Others, disagreeing, hold that lack of enabling means might deprive a man of the liberty under consideration. For example, a person without sufficient money is not free to dine at the Ritz, if he or she wishes to.
There would be no disagreement here if both sets of authors were not thinking and talking about one and the same object—that aspect of freedom which consists in being able to act as one wishes or do as one pleases.
What all this comes to can be summed up by advising readers that this book about six great ideas is not concerned with psychology. It is not concerned with what goes on in people’s minds when they think, or what concepts or notions they have in their minds and employ to think with. It is concerned solely with what they have before their minds when they engage in thinking—with objects they are together considering and about which they and other human beings over the centuries have raised questions and, in answering them, have either agreed or disagreed.
For anyone who is incurably addicted to the subjective sense in which the word “idea” is used by most people, I would be willing to drop the word entirely and substitute “object of thought” for it. But I would much prefer retaining the word and have my readers remember that, as I am using it in a book about six great ideas, I am always writing about six great objects of thought that all of us can focus our minds on, not about the particular concepts or notions that each of us may employ in order to do that.
So far, then, Plato was right. Ideas, as objects of thought, do exist. The idea of truth or of justice does not cease to exist when I cease to think about it, for others can be thinking about it when I am not. However, unlike the chair I am sitting on or the book you are holding in your hand, which does not cease to exist as a perceptible object when no one is perceiving it, objects of thought do cease to exist as intelligible objects when no one at all is thinking about them.
There would be stars and atoms in the physical cosmos with no human beings or other living organisms to perceive them. But there would be no ideas as objects of thought without minds to think about them. Ideas exist objectively, but not with the reality that belongs to physical things. On that point, Plato was wrong.