Now what does that mean?

      Logic is putting your thoughts in order. It's a way to think so that you come to right conclusions.

Inferences are implications, and part of logic is recognizing what a statement implies and what it doesn't.

A fallacy is a mistake.

A formal fallacy is a mistake in the formulation of an argument, or the use of an implication that is invalid, or does not follow.

An informal fallacy is a mistake in the meanings of the terms used.

      To learn logic is to learn the rules of clear and correct thinking.

      Aristotle called logic the organon, or instrument, of all science. All meaningful thinking and communication is dependent upon logic for its weight and force. As we shall see, logic is undeniable: In order to attempt to refute it, one has to use it... thereby affirming it. The basic laws of logic are not arbitrary, but necessary.

For example: One cannot deny the law of non-contradiction without using the law of non-contradiction in the denial. (The law of non-contradiction states that something cannot both be "A" and "non-A" at the same time, and in the same relationship.) If I said "Logic does not apply to this sentence" I'd be using the laws of logic to communicate the idea. That is, of course unless it was really a true sentence, and logic didn't apply. If it was true, and the laws of logic didn't apply, then the law of non-contradiction wouldn't hold. In that case the sentence would be allowed to mean what it doesn't mean!!

      See the problem here? Logic is irrefutable, undeniable and necessary to intelligible communication. Here's a better example:

      It's like saying "I can't speak a word in English." What's wrong with that sentence? Obviously, in making that statement, the statement itself has been negated, because the speaker had to speak English in order to communicate the idea that he or she couldn't speak English. It is a self-refuting affirmation. In philosophy this is called self-stultification. "I don't exist" is another example, for one has to exist in order to make the statement.

      The conscious use of logic in our thinking will help us to identify, understand and solve problems in virtually every aspect of our lives. It can help us understand society and set us free from prejudice, provincialism and poor reasoning. In philosophy it can afford us some distance from our own beliefs as well as those of others and allows us to view them with objectivity. We will be able to absorb information from the news media more critically, become sensitive and aware of implications and inferences in novels, movies and television shows, leaving us less susceptible to propaganda. Omissions and evasions in political rhetoric and advertising will become clear, and we will become more adept at recognizing good argumentation and evidence.

      In logic, by the way, the term argument has a specific meaning other than the one it's associated with in common usage. It has no associations in this context of strife, or emotionally heated exchange. An argument is simply this: A group of propositions (statements, or assertions) in which one proposition provides support or grounds for the truth of another proposition which is claimed to follow from it, or be inferred (implied) by it. No raised voices or short tempers need be involved in this argument. Let's look at a classic example of one form of argument: the deductive syllogism (don't flip out, we'll get to the definitions of these terms sooner or later, meanwhile, just pay attention, for cryin' out loud).

1st Proposition: A) All men are mortal. (major premise)
2nd Proposition: B) Socrates is a man. (minor premise)
Therefore:
3rd Proposition: C) Socrates is mortal (Conclusion)