Setting: A small South London Pub, The White Swan, (Dirty Duck to the locals). Playing a game of snooker in the back room is John Locke and Bishop George Berkeley. They are arguing.
George: Bugger off, you scrumpy-drinking idiot, I bought the last round! John: Oh please! You clergymen are all the same, always trying to get a free lunch. Now dig your hands into those noticeably deep pockets, and get me a chuffin' pint! George: Fine, but next time you come back from the land of clogs you better bring me a present.
John: I heard that. And make sure it's a proper pint this time, none of this "Lite"ÃÂ crap.
George: God damn it, (looks up and raises his hand apologetically), you don't half moan. First it's the weather now the beer. What's next? John: Well, seeing as you asked I've got a bit of a problem with what you did to the ideas in my Essay in Human Understanding.
I mean please, didn't you understand it? George: Of course I understood it. In fact I quite liked most of it.
John: Is that why you plagiarized it for your Treatise Concerning the Principles of Human Understanding? Nice title by the way, really rolls off the tongue.
George: Bugger off you sarcastic git, at least mine was a little bit creative. And I didn't plagiarize. I just took some of your better ideas and refined them. Do you want me to explain the hard bits for you? John: Sure, I could do with a laugh. It's your shot by the way.
George: Ok. I start with the premise that all knowledge comes from sensory experience.
John: That sounds familiar"ÃÂ¦ George: Shut up. Now because our knowledge is formed from the combination of our sense impressions and nothing can exist without a mind and cannot exist other than in a mind then it so follows that without a mind "ÃÂ nothing can exist! Or, to put it another way, esse is percipi. That means "to be is to be perceived."ÃÂ John: I know what essi is percipi means.
George: Sorry I forgot that you went to school once. Anyway, take for example, that blue ball.
By watching it go in the pocket I am, in essence, allowing it to exist.
John: Your scoring another five points is what you're doing.
George: Be quiet, you might just learn something. So you see that the image of the ball going in the pocket needed me to see it in order for it to exist. Without me here to see it, it wouldn't be there.
John; That's because if you weren't here, we wouldn't be playing snooker in the first place.
George: Please try and stay with me, the next bits important. So, because nothing can exist outside the mind then, by definition, primary qualities can not exist.
John: What! No you've got it all wrong. You have to distinguish between ideas and the qualities in objects that cause the ideas in the first place. Firstly you have Primary qualities which are the qualities which do not change with perception: extension, motion, figure, solidity and number. These Primary qualities produce ideas in us in the form of secondary qualities.
Secondary qualities like colour, smell, taste, sound, heat and cold do vary with perception because they are within our mind. Both of these qualities are produced by tertiary qualities or the active power.
George: No! Think about it. The way you defined Primary qualities means that they are outside of the mind but, in reality, these properties are really just ideas in our minds. Take for instance your Primary property of motion.
John: That's definitely a property of the object.
George: Shush. Now as you watch the last red ball speed across the table and disappear, what are you really seeing? John: I'm seeing that I'm losing the game. I wish you wouldn't keep emphasizing your points by potting balls.
George: Stop moaning. Now where was I, oh yes, motion. What your really seeing is a succession of ideas in your mind. Think about it motion is only perceived because of its relationship to other objects in our field of vision. Say for instance that the table was moving in the opposite direction to this black ball, and although the ball would still be moving into the pocket at the same speed you would perceive it as doing so twice as fast. That proves that not only are Primary qualities in the mind but also I've won the game. Your round loser.
John: Hang about. By your definition then there is no real distinction between primary and secondary qualities? George: That's right. By your definition Primary qualities would have to exist outside the mind and as we both know that is just not possible, or at least not perceivable to us mere mortals. Right God? (looks up again).
John: I guess I'll get the beers in then.