Ron’s Logic Boot Camp

The business of logic is analysis & appraisal of arguments.

Arguments are formed from propositions.

There are two roles for propositions in arguments.

1. Premise

1. Premises are asserted as evidence or support for a conclusion

2. Every argument must have at least one premise

2. Conclusion

1. Conclusions are derived from, supported by, inferred from premises

2. Every argument has exactly one conclusion

An argument asserts both

3. That the above supportive relationship, and
4. That the premises and conclusion are true.

Standard Form

Premise 1

Premise 2

Premise 3

etc.

\ Conclusion

Arguments come in three favors: deductive, inductive & fallacious

Deductive Arguments

1. The truth of the premises guarantees the truth of the conclusion
1. It has a valid structure
2. Validity: If the premises were true, the conclusion could not be false

2. Soundness (a truth claim): An argument is sound if it is both
1. Valid &
2. The premises are in fact true

Inductive Arguments

3. The truth of the premises provides support for the truth of the conclusion
1. Inductive arguments are either "strong" or "weak”
2. It is possible to have all true premises and a false conclusion

4. Six common forms of inductive argument:
1. Assert a causal relationship
2. Conclude something about the future based on the past
3. Conclude something about the past based on present evidence
4. Conclude a particular kind of similarity holds between things based on other known similarities
5. Conclude something about a particular case based on what usually or frequently happens
6. Generalize based on a sample of observations or experiments

Fallacious Arguments (a.k.a. Fallacies)

5. Mistakes in reasoning which appear to be arguments

6. These are divided into formal and informal fallacies.
1. Formal fallacies are those with structural errors.
2. Informal fallacies are those with usage errors.

7. Ambiguity & Vagueness

8. There are literally hundreds of types.