9. Locke and Berkeley

- The Empiricists

- John Locke, George Berkeley, David Hume

For the time line - Descartes writes Meditations in 1641, Newton writes Mathematical Principles of Natural Philosophy in 1687 and in 1690 Locke writes An Essay Concerning Human Understanding. Berkeley writes one of his most famous works A Treatise Concerning the Principles of Human Knowledge in 1710. Hume writes An Enquiry Concerning Human Understanding in 1748. Kant writes Critique of Pure Reason in 1781.

We'll start with John Locke.

Locke can in some sense be seen as trying to naturalise Descartes. Descartes had been a champion of mechanistic philosophy. Descartes work along with Galileo's laid the foundations for Newton's work. This allowed that mathematically precise physics to develop.

Locke can be seen to hold much the same views about the mind as Descartes, except some major disagreements about the nature and source of innate ideas as well as Locke is an empiricist not a rationalist. So he doesn't think the way we achieve knowledge is by reason but rather we discover the mathematical nature of reality by experimentation and careful observation.

The Attack on Innate Ideas.

Descartes had argued that there were innate ideas. He said that all clear and distinct ideas are innate and these ideas are necessarily true and known by reason. The first and foremost idea is I think therefore I am and then you have various mathematical concepts, logical concepts. Locke develops two arguments against innate ideas.

The first argument is that not every person agrees or has these ideas. The second is that there is an alternative explanation that all ideas come from experience.

The First Argument

- If there really were innate ideas there would be universal agreement. This argument relies on Descartes claim that one is immediately and infallibly aware of the contents of one's own mind. Locke and Descartes both held that it is inconceivable that there could be something in your mind which you are unaware of. So Locke says that if there were these innate ideas then we would be aware of them and understand them and we wouldn't disagree on them. But we do disagree, so this mustn't be true.

- If there were innate ideas they would have to be there at birth, so even infants would have to be aware of them. But they aren't. So the idea is that infants and idiots don't have these ideas, but if they are supposed to be born in, then they should. So Locke is making an empirical claim, we know by observation that these things are true. So Descartes' claim that the clear and distinct ideas are innate is wrong.

The Real Issue

But the argument over whether these ideas are innate is besides the point that Locke wants to make. Locke really wants to assert that all knowledge arises from experience. This is the Empiricists claim. So if it does turn out that some aspects of human reasoning are innate, there is still the question of whether it could have arisen in response to experience.

The Second Argument

His second argument is that we can account for all human knowledge solely on the basis of our experience. This includes everything, Mathematics, logic, language, physics, biology, literature, psychology, everything. So the goal Locke has is to show that ultimately all ideas come from experience.

Locke makes a distinction between two kinds of ideas; simple and complex .

Simple ideas are ones that don't have any constituent parts and come directly from experience. So a simple idea might be like a shape or a colour or a sound, so something we pick up immediately from our experience.

Complex ideas are composed of simple ideas. Once you have these two kinds of ideas its easy to explain a whole wide swathe of ideas that we think about. For instance, if I want to think about a unicorn even though there are no unicorns, I've never experienced a unicorn, I can show how my idea of a unicorn is really a complex idea which is composed of simpler ones. I have experiences of horses and also of animals with horns, so I am able to combine those two ideas in the mind to make a complex idea. That is an important idea and one that gets used a lot in constructing empiricist theories.

Simple ideas have one of two sources; Sensation and Reflection. Sensation is the source of our ideas of external objects; eg, tables, chairs, blue, green, hot. cold, sweet, planets. All of those things we get from actually sensing. We are also able to reflect on our mental activity and reflection is the source of our ideas of mental objects; eg willing, doubting, perceiving, believing, reason.

Locke's Theory of Perception

Locke basically accepts Descartes view about perception. There is a physical world, we are in a body and those causally interact and that gives rise to our experience. The colours, sounds and shapes are in the mind and not out there in the world. This is what is usually called Locke's causal theory of perception and Descartes held a causal theory of perception as well. Locke gives names to these ...

Secondary qualities refer to such things as sound, colour, taste etc. These things are not really out there in the world but only in our mind.

The Primary qualities of an object amount to the properties an object has which can be quantified and mathematicised . These things really are in the objects. The only qualities that are really out there and mind independent are the primary qualities.

Primary and Secondary

- Primary properties are mind independent - shape, solidity, motion, all properties which can be quantified.

- Secondary properties are produced in the mind - colour, sound, smell.

Locke on the Self

Locke's question: What makes a person the same over time?

We all feel that we are the same person today as when we were young. But why?

Locke's answer is psychological continuity. You are the same person because you are conscious of your mental life as belonging to a single self.

A Test - Suppose that a new technology is invented that allows us to teleport to far away places. This technology works by scanning your genetic makeup and reproduces an exact copy wherever you need to be going. You don't actually move, they scan you and make an exact duplicate. Unfortunately in order to do this they have to destroy your original body. But the copy on the other side is exactly the same, it has all of the same memories, thoughts, feelings... Locke would say you are the same person. So the question is, the test for you - Would you use this technology or not? This isn't a way for you to figure out if Locke is right or not, it's just a way for you to figure out what you think about Locke's view. Locke's view would say that you shouldn't care if you don't have the same body, what is important is that you have the same psychological continuity, the same stream of consciousness, the same memories, beliefs etc.

This view of Locke's has been a very influential view in the philosophy of personal identity.

Berkeley - Idealism

Berkeley is an idealist, and an idealist is someone who denies that matter exists. Berkeley thinks that the only things which exist are mental things. Everything is an experience. By 'matter' he means the mind-independent stuff that we cannot perceive.

Locke (and Descartes) endorsed the distinction between primary and secondary qualities. But we never see matter, so why believe in it? An Empiricist is someone who thinks that what is real is what you can see, taste, touch, smell and hear. And according to empiricism, the only things that you see, taste, touch and hear are experiences. So empiricists should accept that everything they observe is a mental thing.

Primary qualities are said to resemble the material they represent. Berkeley spends time trying to figure out what that means, How could something mental resemble something physical? If we take that seriously, we have no real way of saying that primary qualities resemble the material things that exist in the world. Berkeley says the very concept of this material that these philosophers are talking about is incomprehensible. This is what is sometimes known as Berkeley's master argument. But the argument was that you cant even conceive of what it would mean for matter to be existing when you weren't looking at it independently of you experiencing it. And the idea is that every time you try to conceive or imagine some object existing mind independently, you are only picturing the object in your mind.

An analogy

Consider the things you see in a video game. Suppose you are playing the Sims and you walk into a room and see a table. If you leave the room when you walk back in the table is still there. When you are not in the room, there is no table still existing there. There is only a bit of code somewhere that says if the player does this, then represent this on the screen. So the table only exists when it is perceived. Or when it is not perceived it does not exist. This is what Berkeley means when he says the essence of things is to be perceived. Then what does this mean? Why do ordinary object cease to exist when we are not perceiving them? Berkeley claims that God is always perceiving the physical world so we can rest assured that the physical world exists.

Berkeley's views are very anti-common sense, the physical world doesn't exist and all that exists are experiences. Berkeley's point is that the empiricists have no reason to believe in matter because they cant see, touch or taste, hear it. All they have access to is experience. So Berkeley is saying, if you are going to be an empiricist, explain why you get to believe in things you have never seen.