propositional

Tutorial 4: Arguments and searching for a counter example

Logical System

11/26/11 10Software

Skills to be acquired in this tutorial:

To learn how to symbolize arguments, and how to judge whether they might be invalid using truth-table methods.

Why this is useful:

We wish to appraise arguments, to do this we have to symbolize them first. Judging the invalidity of arguments by truth-table methods is not particularly important, but it does help to develop skills involving truth and lists of formulas.

Reading

Hausman[2007] Logic and Philosophy Chapter 3

Review

Logical System

There is the idea of setting up a code or convention or dictionary between atomic sentences and capital letters.

There are compound sentences, each of which has a main connective which connects its components.

There are five sentential logical connectives:

'∼' which translates back to 'it is not the case that...'

'.' which translates back to '... and ...'

'∨' which translates back to '... or ...'

'³' which translates back to 'if... then ...'

'≡' which translates back to '... if and only if ...'

Tutorial 1 Introduction, sketch of course, and symbolizing atomic sentences.

Logical System

11/26/11 10 Software

Skills to be acquired in this tutorial:

To become familiar with the notions of argument, valid, invalid, premise, and conclusion. To learn how to symbolize atomic sentences.

Reading

A. Hausman, H.Kahane, P.Tidman, [2007] Logic and Philosophy Chapters 1, 2.1

Tutorial:

The main role of logic is to assess arguments-- to say whether an individual argument is valid or whether it is invalid. In logic, arguments are taken to consist of two components--premises, and a conclusion.

For example,