Logic – Reason Based on Strict Principles for Valid Arguments

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What is logic?

Logic can be described as reasoning conducted or assessed according to strict principles of validity:
Experience is a better guide to this than deductive logic.

The term “logic” came from the Greek word logos. Logic is the study of the principles of correct reasoning – principles governing the validity of arguments.

If Andy is a foo, then Andy is bar.
Andy is a foo.
Therefore, Andy is bar.

If the Thames is a river, then it is wet.
The Thames is a river.
Therefore, the Thames is wet

If Bus->passengers > 50 then bus = crowded.
Bus->passengers = 65.
Therefore, Bus = crowded.

Therefore, C.

A logician will tell us that they are all cases of a particular form of argument known as “modus ponens”. A second feature of the principles of logic is that they are non-contingent, in the sense that they do not depend on the way that the world is, whereas science for example does. Chemistry works like it does because the elements in the periodic table are how they are. Planes fly because of the laws of physics. However, the principles would still apply even if the whole world’s properties changed. “if it is raining, then it is raining” must be true. We can easily see that this is indeed the case, whether or not it is actually raining.

Why is it useful?

The most immediate and obvious benefit from studying logic is that it can allow you to improve the quality your arguments.  A second and closely related benefit will be an improved ability to evaluate the arguments of others. You can see how arguments should and shouldn’t be constructed. For example, someone might be saying:

Buy this car, because this car is red.
This car is red,
Therefore, buy this car.

But why should I buy the red car and not the green car? Just because someone said so?

If the car is red, the car is fast.
The car is red.
Therefore, the car is fast.

Could be more reason to buy the car.

More information here.

How do I use it?

Below you will find the 10 Commandments of this principle, which explain better how and where this type of thinking could best be used. Underneath that you will also find a quote by Epicurus surrounding different logics that can be put into use when talking about God.




Oxford Dictionary [Online]. [Accessed 27 Feb 2014]. Available from: