IDENTIFYING THE ARGUMENT FOR THE THESIS

Bob Corbett

PHIL 1010 01: June 5th until July 28th, 2000

Class-lecture

As I've already indicated a number of times (and will do MANY more times), the unit of discourse in critical thinking is the argument.

An argument has two parts:

  1. The thesis
  2. The set of reasons and considerations given for believing that the thesis is either true, or at least the best or most likely of the options available.

I like to speak of both

-- reasons
and
-- considerations

since what is offered in defense of the thesis is not always a reason. I leave open the purposely vague notion of "considerations" as anything which seriously contributes to coming to see the thesis as either true or preferable to other alternatives.

I can give a few examples of considerations, but it is a wide open field. It will include such things as clarifications, historical background, key examples, definitions of key terms and on and on and on.

In unison the argument should be viewed as an

IF THEN

structure.

IF: this set of reasons and considerations are:

  1. true and persuasive
  2. logically connected to the thesis (I'll deal with the logic in the next lecture)

THEN: The thesis is supported.

Again, let me repeat:

The "if" part of the argument is the set of reasons and considerations.

The "then" part of the argument is the thesis.

The argument is understood as conditional: If the set of arguments and considerations are adequate, then the conclusion is reliable (true or the best option).

============

Notice an important fact connected with critical thinking. Since the smallest unit of meaningful talk is the ARGUMENT (the whole if . then proposition), and not the claim (the thesis) it is possible that often we could be discussing an argument in which the thesis is IDENTICAL in both arguments.

Suppose you say:

Going to Chicago by train is better than going by car because the train is more ecological.

And I say:

Going to Chicago by train is better than going by car since one passes through some interesting little towns and the scenery is great.

Now your "argument" is

If: the train to Chicago is more ecological than the car

then: Going to Chicago by train is better than going by car.

My argument is

If the train to Chicago passes through some interesting little towns and the scenery is great

then: Going to Chicago by train is better than going by car.

Both of us hold the same thesis: Going to Chicago by train is better than going by car.

============

If we were dealing in mere sentences then we would seem to agree. Both of us believe that going to Chicago by train is better than going by car.

But we don't agree at all. You have a different set of reasons and considerations than I. We are in severe disagreement.

We might combine the two sets of reasons into one argument which we both accept, then we would have come into agreement. You might come to accept my set, or me your set. We might work out a slightly different set of arguments and considerations than either of us had before and come to agree.

Lots of possibilities.

The point is: the unit of discourse in critical thinking is the

If A, then B argument form

in which A is the set of reasons and considerations

and B is the thesis.

Questions are welcome.


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Bob Corbett corbetre@webster.edu