The Art of Argument

I would guess that 95% of the folks who regularly read and comment on this blog know how to express their opinions and make arguments. It doesn't matter whether they agree or disagree with what I post here. The vast majority state their position and then provide some rationale for why they've drawn their conclusions.

Unfortunately, I have two or three readers who don't understand the art of argument nor conversation. These folks generally offer conclusions, but provide no information on how these conclusions were reached. Not only that, but if you ask them the basis for their conclusions, they refuse to answer OR they answer with yet another unsubstantiated conclusion.

So, as a public service to these two or three people, I'm going to feature some information below about how valid arguments are constructed. The information comes from Wikipedia.

In logic, an argument is a set of one or more meaningful declarative sentences (or "propositions") known as the premises along with another meaningful declarative sentence (or "proposition") known as the conclusion. A deductive argument asserts that the truth of the conclusion is a logical consequence of the premises; an inductive argument asserts that the truth of the conclusion is supported by the premises. Deductive arguments are valid or invalid, and sound or not sound. An argument is valid if and only if the truth of the conclusion is a logical consequence of the premises and (consequently) its corresponding conditional is a necessary truth. A sound argument is a valid argument with true premises.

Each premise and the conclusion are only either true or false, i.e. are truth bearers. The sentences composing an argument are referred to as being either true or false, not as being valid or invalid; deductive arguments are referred to as being valid or invalid, not as being true or false. Some authors refer to the premises and conclusion using the terms declarative sentence, statement, proposition, sentence, or even indicative utterance. The reason for the variety is concern about the ontological significance of the terms, proposition in particular. Whichever term is used, each premise and the conclusion must be capable of being true or false and nothing else: they are truthbearers.

In other words, if you are interested in engaging in a meaningful conversation with me or other readers, declarative statements need to have some premises that they are built upon.

If you choose to continue to offer conclusions without substantive reasons offered, then it may mean that you are offering a logical fallacy or an elliptical argument. (Of course, it may simply mean that you like to be argumentative and an irritant.)

A fallacy is an invalid argument that appears valid, or a valid argument with disguised assumptions. First the premises and the conclusion must be statements, capable of being true and false. Secondly it must be asserted that the conclusion follows from the premises. In English the words therefore, so, because and hence typically separate the premises from the conclusion of an argument, but this is not necessarily so. Thus: Socrates is a man, all men are mortal therefore Socrates is mortal is clearly an argument (a valid one at that), because it is clear it is asserted that that Socrates is mortal follows from the preceding statements. However I was thirsty and therefore I drank is NOT an argument, despite its appearance. It is not being claimed that I drank is logically entailed by I was thirsty. The therefore in this sentence indicates for that reason not it follows that.

Elliptical Arguments
Often an argument is invalid because there is a missing premise the supply of which would make it valid. Speakers and writers will often leave out a strictly necessary premise in their reasonings if it is widely accepted and the writer does not wish to state the blindingly obvious. Example: All metals expand when heated, therefore iron will expand when heated. (Missing premise: iron is a metal). On the other hand a seemingly valid argument may be found to lack a premise – a ‘hidden assumption’ – which if highlighted can show a fault in reasoning. Example: A witness reasoned: Nobody came out the front door except the milkman therefore the murderer must have left by the back door. (Hidden assumption- the milkman was not the murderer).