I. "ARGUMENT" IN PHILOSOPHY
(An argument in philoosphy does not imply a disagreement or quarrel between persons. Although there may be disagreement concerning the claim being argued, there need not be a disagreement.)
A sound argument makes clear to the hearer or reader that to accept the reasons offered while not accepting the claim or conclusion is to be in contradiction with yourself. (that is what it means when we say that the claim follows from the reasons.)
Good reasons are (a) true, (b) relevant, and (c) taken together they should be sufficient to counter any contrary considerations and establish the likelihood, if not the certainty, of the claim being true.
Reasons which fail to meet one or more of these criteria weaken or destroy the overall soundness of the argument.
A good or valid inference is where the reasons, were they true, would be sufficient to establish the claim being true. It is where the claim clearly follows from the reasons.
The test for a valid inference is to see if it is possible without contradiction to accept (hypothetically) the reasons given as true while denying the claim. If you can imagine and state any circumstances where the reasons could be true and the claim false, then the inference is invalid. On the contrary, if no circumstance can be imagined where the reasons could be true and the claim false, the inference is valid.
If the test is made and you can imagine circumstances which could make the claim false while the reasons are true but the evidence indicates that those circumstances do not exist, then the inference establishes the likelihood of the conclusion but not its certainty. (In this case, the inference would be a good inductive inference, but an invalid deductive inference.)
An argument can have a valid or good inference even when it has untrue premises.
An invalid inference is where the reasons, were they true, would be insufficient to establish the claim being true. It is where the claim does not follow from the reasons.
V. HOW TELL WHEN THE REASONS OR EVIDENCE IS SUFFICIENT?
1. It depends on the subject area. Some areas are necessarily more stringent than others.
2. It depends on the kind of evidence or sources of knowledge being relied upon.
3. It depends to some extent on how knowledgable the audience is.
4. Sometimes it is very difficult to tell.
Does it depend on opinion? I.e., Who's to say?
1. There are reasoned ways out of the pitfalls of relativism and skepticism. Know them.
2. Distinguish between opinion without reasoned judgment from opinion with it.
3. Sufficient evidence is evidence that would be convincing to
a person who is
1. Your own.
2. You can defer to someone else's judgment only by you endorsing that person's judgment. Your deference to the other person's judgment is a judgment of your own.
3. Your own judgment (as is anyone else's) remains finite and fallible and is only as good as your own reasoning can make it to be.
4. Other people's judgment to the contrary counts as counter-evidence only if it meets the criteria listed above.
VI. CRITICAL EVALUATION OF ARGUMENT OUTLINE
VI. SOME BASICS ABOUT TRUTH CLAIMS
1. Any claim, any candidate for belief, makes a claim about truth.Even the claims, "No truth can be found." Or "There is no truth.", make claims about truth -- self-contradictory claims.2. In making or being a claim about truth, in risking being right or correct, a belief also risks being wrong.
3. In other words, any claim could possibly be wrong. We cannot escape the risk.
4. To believe a claim is to take a stand against a claim that contradicts it.
5. No two contradictory claims can both be true (literally and on the face of it).
6. If two contradictory claims each have some truth, then it is because one or both of them is not entirely or literally true.
7. But we don't know that one or the other is true, or to what extent it is true, until we have examined them critically.
8. Believing a claim, even feeling certain about it, doesn't constitute knowing that it is true, nor does it make it true.
9. To determine a claim's truth, we have to examine the relationship between the claim (the map) and the reality (the territory) it purports to represent.
10. This requires that we have some kind of independent access (in our own persons) to that reality -- through direct observation, direct evidence, or indirect evidence.This is where good reasons and rational argumentation comes into play.11. Simply coming up with an answer, belief, or claim on one's own doesn't make it true.