The Metaphysics of Philosophy, Knowledge and Morality Chapter 14

Chapter 14

Common sense

Common sense (Greek: koine aisthesis, Latin: sensus communis) means shared perception. It’s a stretch to call shared perception “reason”. We don’t have a good definition for reason, the intuitive definition is “if you think what I think, you’re reasonable, if you disagree with me, you’re unreasonable”. Clearly, that’s not good enough, but we don’t have any better.

Discussions take place at three levels: 1. Common Sense; 2. Cross-Referenced Common Sense; 3. No Common Sense.

1. Common Sense (CS) - I take it for granted that you know what I mean when I say “table”, “chair”, “sit”, “live”, “die”, “suffer”, “happy”, “understand”, “know”, etc. The benefit of this level is that you can make your point very quickly. The disadvantage is that you’ll only agree with those who agree with you anyway. This is the level for feel-good discussions amongst like-minded people. It’s useless for sorting out disagreements.

2. Cross-Referenced Common Sense (CRCS) - I take it for granted that if I give you additional information, you’ll agree with me about the meaning of words and concepts. You may not accept “table” to mean “you know what I mean”, but you’ll accept my definition as “three- or four-legged utensil people sit around when they eat, talk, etc.”. This is the level for sorting out minor disagreements between more or less like-minded people.

3. No Common Sense (NCS) - I don’t take anything for granted, I play the Ultimate Perfectionist when it comes to definitions. If you try to define table by cross-referencing it with “sit around”, I’ll ask you to define “sit” and “around”. When you cross-reference these terms, I’ll ask you to define the new terms you used as cross-reference. This goes on and on till the end of time. Nothing is definable at this level, and nothing can be agreed. (If you read maths books, you’ll find that the basic notions can’t be defined, they must be accepted on a “you-know-what-I-mean” basis. It’s the same with language.)

Notice that “mentalists” trying to control argumentation switch levels back and forth. They refer to Common Sense when it benefits them, and play the Ultimate Perfectionist when that serves their purpose. This usually occurs in social and political debates, such as on gay marriage. A mentalist will appeal to your Common Sense in saying “everyone has the right to pursue happiness as they see fit”, but when you say gay sex is unnatural, they’ll become the Ultimate Perfectionist and demand that you provide a flawless definition of “unnatural”. At this No Common Sense level, you can’t define anything, and so the mentalist declares victory. If you ask the mentalist to provide a flawless definition for “right”, “happiness”, “pursue” and “fit”, they won’t be able to do that, and then you can declare victory. It’s a good technique to expose mentalists when they switch levels. You can either stay at the same level or you can switch to the level of the mentalist and announce what’s happening.

Don’t be surprised to find that at the CS and CRCS levels you’ll only agree with people who agree with you anyway, and that at the NCS level you won’t agree about anything. That’s the nature of discussions.