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.”
“I get it.”
“So when it was a question of ‘extended’ reality, Locke agreed with Descartes
that it does have certain qualities that man is able to understand with his reason.”
“It shouldn’t be so difficult to agree on that.”
“Locke admitted what he called intuitive, or ‘demonstrative,’ knowledge in
other areas too. For instance, he held that certain ethical principles applied to
everyone. In other words, he believed in the idea of a natural right, and that was a
rationalistic feature of his thought. An equally rationalistic feature was that Locke
believed that it was inherent in human reason to be able to know that God exists.”
“Maybe he was right.”
“About what?”
“That God exists.”