Introduction To Logic

In a republican nation, whose citizens are to be led by reason and persuasion and not by force, the art of reasoning becomes of the first importance.

- Thomas Jefferson

Today school reopens. First day of 2005/06 Semester one. What a great feeling to finally go back to studies again after such a long holiday.

Today's lecture is at LT8 4-6. Newly renovated LT8, chairs are really very comfy. The only drawback is that aircons are much stronger now.

Have to thank Jieting for helping me buy the dvds and also the New Media reading package for me.

Basically the first lecture is just introduction to the course proper.

There is a total of 12 lectures and 9 tutorial sections which are not compulsory.

Important terms and concepts:

Argument: It's a piece of reasonsing with a set of statements, one of which(the conclusion) is maintained to be true on the strength of the others(the premises)

Argument=premises+conclusion.

Every argument has exactly one conclusion and at least one preimise.

Conclusion-indicator: A word or phrase signaling the presence of a conclusion(in an argument).
Examples are "therefore", "so", "hence"', "thus", "it follows that", "as such", "we may conclude that", and so on.

Premise-indicator: A word or phrase signaling the presence of a premise(in an argument)
Examples are "since", "because", "as", "for", "due to the fact that", and so on.

Enthymeme: An argument, one of whose premises(or perhaps even the conclusion) is implcitly suppressed, though intended as present.

Arguments have structure. If you are arguing for something(a certain claim), you should be clear on the structure of your own argument. Likewise, if someone else is arguing for something, and you wish to rebut that argument, then you should be clear on what the structure of that person's argumnet is.

An argument is deductive just in case it is intended that the conclusion is guranteed by the premises.

If the conclusion is indeed guranteed by the premises, then the argument is (said to be) deductively valid. Otherwise, it is deductively invalid.

An argument is inductive just in case it is intended that the conclusion is made probable(though not guranteed) by the premises.

If the conclusion is indeed made probable by the premises, then the argument is(said to be)inductively strong. Otherwise it is inductively weak.