Friday, April 25, 2008

Logical Concepts

We talked about recognizing arguments from non-arguments. Now I'll show you the tools used to distinguish good arguments from bad ones so you don't get sold bullshit any longer.

2 key questions are asked when evaluating arguments:
1. Are the premises true?
2. Do the premises provide good reason to accept the conclusion?

We'll discuss the first question in later lessons. Right now, we'll focus on the second question.
Before we can evaluate an argument, we need to understand clearly what kind of argument is being offered.
There are important differences between the two standard types of arguments:
1. Deductive arguments
2. Inductive arguments

All arguments claim to provide support - that is, evidence or reasons - for their conclusions. But arguments differ in the amount of support they claim to provide.

DEDUCTIVE ARGUMENTS try to prove their conclusions with rigorous, inescapable logic.
INDUCTIVE ARGUMENTS try to show that their conclusions are plausible or likely or probable give the premise(s).

Some example of deductive arguments:
All humans are mortal
Socrates is human
Therefore, socrates is mortal

(Later, I'll show you patterns of reasoning that slip by the concious mind...such as the above...often whether it is indeed true or not:
A is B
C is A
therefore, C is B


A is B
B is C
therefore, A is C.

This is literally the 'pattern of thought' or put another way...'how people think and reason in everyday life if you were to put it onto paper'.

This is why people tend to be easily manipulated.

Because people use these patterns of thought (already ingrained in us) to bypass your 'radar' so to speak. This is incredibly persuasive for those who want to persuade you, and can be harmful for those who do not know how to reason logically and evaluate arguments.)

Another example:
If the president lives in the White House, then he lives in Washington, D.C.
The president does live in the White House.
So, the president lives in Washington D.C.

Notice how the conclusions of the arguments flow from the premises with a kind of inescapable logic. Each conclusion follows necessarily from the premises; this means that, given the premises, the conclusion could not possibly be false. Arguments are deductive when their premises are intended to provide this kind of rigorous, airtight logical support for their conclusions.

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