What is logic?
Logic is hidden behind every conversation, joke, story or argument. Logic is necessary in order to be able to have an understandable form of communication. Without it, conversation, jokes, stories or arguments could not take place.
Aristotle was a famous old bloke from Ancient Greece who thought a lot about a lot of stuff, but most importantly, for this subject, he thought about thought; what it was and how it takes place. He said that thought has laws. There are rules which enable the process of thinking to happen. The most crucial law of thought is the law of identity. The law of identity states that:
A = A.
The equals sign is another way of saying the same as. Anything can be put in the place of ‘A’. For example, 'A = A' can stand for ‘that orange’ is ‘that orange’,’ you’ are ‘you’ and ‘logic’ is ‘logic’. This means that a thing is identical with itself.
The other thing that Aristotle said was that if it follows that if everything is the same with itself and that this is a law, then it cannot be a contradiction. This thought is expressed in the law of non-contradiction. It cannot be that:
ORANGE = NOT ORANGE
We cannot think this orange is both an orange and not an orange. Let’s put this in a scenario: let’s say you and your mate Kinglsy arranged to go out on the pull. You both agreed to meet outside Tottenham Court road tube station at 10:00pm.
You are standing there, it’s pouring down with rain and Kingsly isn’t there. You try calling him, but it’s forwarding to 02 voicemail and taking your last bit of credit and your thinking, ‘I hope this twat has got a good reason why I’ve been standing here for half an hour like a mug in the rain.’ He turns up causally at 11.00pm. You’re very angry, so you say, “Where the hell have you been?”
Kingsly says, “Mate, by 10.00 pm I did mean 10.00 pm, but I didn’t mean 10.00 pm and I meant 11.00pm. Do you know what I mean? “
This is an example of a contradiction and is not a reason at all, let alone a good one. When we are met with a contradiction we are just utterly confused. We have to ask, “Kingsly what the hell are you on about?” Kingsly then goes on to say some other nonsense because he has taken acid. Kingsly is no longer using the laws of identity to express himself. This raises an important point as it doesn’t matter how logical you are being if the other person is being illogical, a conversation cannot take place.
Now, it seems pretty obvious that things are what they are and are not what they are not. Therefore, when we talk about whether an object is either an orange or not orange, whether it is either 10.00pm or not 10.00pm, we are referring to the last law of thought called the law of excluded middle. An example is as follows:
I am a human being
Or
I am not a human being.
One of these statements has to be true. However, they cannot both be true or they cannot both be false. When Aristotle thought about the laws of thought thousands of years ago, he realised that human beings cannot think outside of these laws. As a last exercise, try it yourself. Can you think of an orange and not an orange, which are both properties of the same thing? Can you understand what Kingsly means by 10.00pm and not 10.00pm? Or do you think it is true that you are a human and not a human?
If you could think of any of these things you may have a hard time explaining it.....
Ellese Elliott
The Philosophy Takeaway 'Logic' Issue 45
