“I don’t care if he laughs every time he thinks of Berkeley. But what is so funny about that particular philosopher?”
“We’ll have to wait and see.”
“But today is the day you’re going to talk about him, isn’t it?”
“Yes, today is the day.”
Alberto made himself comfortable on the sofa. Then he said:
“Last time we sat here I told you about Descartes and Spinoza. We agreed that they had one important thing in common, namely, that they were both rationalists.”
“And a rationalist is someone who believes strongly in the importance of reason.”
“That’s right, a rationalist believes in reason as the primary source of knowledge, and he may also believe that man has certain innate ideas that exist in the mind prior to all experience. And the clearer such ideas may be, the more certain it is that they correspond to reality. You recall how Descartes had a clear and distinct idea of a ‘perfect entity,’ on the basis of which he concluded that God exists.”
“I am not especially forgetful.”
“Rationalist thinking of this kind was typical for philosophy of the seventeenth century. It was also firmly rooted in the Middle Ages, and we remember it from Plato and Socrates too. But in the eighteenth century it was the object of an ever increasing in-depth criticism. A number of philosophers held that we have absolutely nothing in the mind that we have not experienced through the senses. A view such as this is called empiricism.”
“And you are going to talk about them today, these empiricists?”
“I’m going to attempt to, yes. The most important empiricists—or philosophers of experience—were Locke, Berkeley, and Hume, and all three were British. The leading rationalists in the seventeenth century were Descartes, who was French; Spinoza, who was Dutch; and Leibniz, who was German. So we usually make a distinction between British empiricism and Continental rationalism.”
“What a lot of difficult words! Could you repeat the meaning of empiricism?”
“An empiricist will derive all knowledge of the world from what the senses tell us. The classic formulation of an empirical approach came from Aristotle. He said: ‘There is nothing in the mind except what was first in the senses.’ This view implied a pointed criticism of Plato, who had held that man brought with him a set of innate ‘ideas’ from the world of ideas. Locke repeats Aristotle’s words, and when Locke uses them, they are aimed at Descartes.”
“There is nothing in the mind... except what was first in the senses?”
“We have no innate ideas or conceptions about the world we are brought into before we have seen it. If we do have a conception or an idea that cannot be related to experienced facts, then it will be a false conception. When we, for instance, use words like ‘God,”eternity,’ or ‘substance,’ reason is being misused, because nobody has experienced God, eternity, or what philosophers have called substance. So therefore many learned dissertations could be written which in actual fact contain no really new conceptions. An ingeniously contrived philosophical system such as this may seem impressive, but it is pure fantasy. Seventeenth- and eighteenth-century philosophers had inherited a number of such learned dissertations. Now they had to be examined under a microscope. They had to be purified of all hollow notions. We might compare it with panning for gold. Most of what you fish up is sand and clay, but in between you see the glint of a particle of gold.”
“And that particle of gold is real experience?”
“Or at least thoughts that can be related to experience. It became a matter of great importance to the British empiricists to scrutinize all human conceptions to see whether there was any basis for them in actual experience. But let us take one philosopher at a time.”
“Okay, shoot!”
“The first was the Englishman John Locke, who lived from 1632 to 1704. His main work was the Essay Concerning Human Understanding, published in 1690. In it he tried to clarify two questions. First, where we get our ideas from, and secondly, whether we can rely on what our senses tell us.”
“That was some project!”
“We’ll take these questions one at a time. Locke’s claim is that all our thoughts and ideas issue from that which we have taken in through the senses. Before we perceive anything, the mind is a ‘tabula rasa’—or an empty slate.”
“You can skip the Latin.”
“Before we sense anything, then, the mind is as bare and empty as a blackboard before the teacher arrives in the classroom. Locke also compared the mind to an unfurnished room. But then we begin to sense things. We see the world around us, we smell, taste, feel, and hear. And nobody does this more intensely than infants. In this way what Locke called simple ideas of sense arise. But the mind does not just passively receive information from outside it. Some activity happens in the mind as well. The single sense ideas are worked on by thinking, reasoning, believing, and doubting, thus giving rise to what he calls reflection. So he distinguished between ‘sensation’ and ‘reflection.’ The mind is not merely a passive receiver. It classifies and processes all sensations as they come streaming in. And this is just where one must be on guard.”
“On guard?”
“Locke emphasized that the only things we can perceive are simple sensations. When I eat an apple, for example, I do not sense the whole apple in one single sensation. In actual fact I receive a whole series of simple sensations—such as that something is green, smells fresh, and tastes juicy and sharp. Only after I have eaten an apple many times do I think: Now I am eating an ‘apple.’ As Locke would say, we have formed a complex idea of an ‘apple.’ When we were infants, tasting an apple for the first time, we had no such complex idea. But we saw something green, we tasted something fresh and juicy, yummy ... It was a bit sour too. Little by little we bundle many similar sensations together and form concepts like ‘apple,”pear,”orange.’ But in the final analysis, all the material for our knowledge of the world comes to us through sensations. Knowledge that cannot be traced back to a simple sensation is therefore false knowledge and must consequently be rejected.”
“At any rate we can be sure that what we see, hear, smell, and taste are the way we sense it.”
“Both yes and no. And that brings us to the second question Locke tried to answer. He had first answered the question of where we get our ideas from. Now he asked whether the world really is the way we perceive it. This is not so obvious, you see, Sophie. We mustn’t jump to conclusions. That is the only thing a real philosopher must never do.”
“I didn’t say a word.”
“Locke distinguished between what he called ‘primary’ and ‘secondary’ qualities. And in this he acknowledged his debt to the great philosophers before him— including Descartes.
“By primary qualities he meant extension, weight, motion and number, and so on. When it is a question of qualities such as these, we can be certain that the senses reproduce them objectively. But we also sense other qualities in things. We say that something is sweet or sour, green or red, hot or cold. Locke calls these secondary qualities. Sensations like these—color, smell, taste, sound—do not reproduce the real qualities that are inherent in the things themselves. They reproduce only the effect of the outer reality on our senses.”
“Everyone to his own taste, in other words.”
“Exactly. Everyone can agree on the primary qualities like size and weight because they lie within the objects themselves. But the secondary qualities like color and taste can vary from person to person and from animal to animal, depending on the nature of the individual’s sensations.”
“When Joanna eats an orange, she gets a look on her face like when other people eat a lemon. She can’t take more than one segment at a time. She says it tastes sour. I usually think the same orange is nice and sweet.”
“And neither one of you is right or wrong. You are just describing how the orange affects your senses. It’s the same with the sense of color. Maybe you don’t like a certain shade of red. But if Joanna buys a dress in that color it might be wise to keep your opinion to yourself. You experience the color differently, but it is neither pretty nor ugly.”
“But everyone can agree that an orange is round.”
“Yes, if you have a round orange, you can’t ‘think’ it is square. You can ‘think’ it is sweet or sour, but you can’t ‘think’ it weighs eight kilos if it only weighs two hundred grams. You can certainly ‘believe’ it weighs several kilos, but then you’d be way off the mark. If several people have to guess how much something weighs, there will always be one of them who is more right than the others. The same applies to number. Either there are 986 peas in the can or there are not. The same with motion. Either the car is moving or it’s stationary.”
