Some Ways to Justify Claims

1. We can appeal to what is intuitively obvious. Some might want to say that we know about our own existence intuitively.

2. We can appeal to empirical investigation. We determine whether it is snowing by checking our senses.

3. Sometimes, we appeal to testimony. I was not in Dallas when Kennedy was killed, so I have to trust the testimony of other people.

4. We might appeal to analogies. Someone might say that we know that Canada's economy will be stronger because we can draw an analogy with another country in a similar circumstance, whose economy is now stronger.

5. Some may count revelation as adequate justification for a claim. That may support the existence of God, although it is certainly not the only way one might argue for that.

6. Someone may appeal to deduction to support a claim. For instance, one may decide that 1 + 1 = 2 is deducible from other, more basic axioms of mathematics.

7. We can appeal to the consequences of a claim, or to the consequences of its opposite. For example, we may say that it is wrong to murder babies, because if we did, we would end up with great trauma for many people, and fewer people in the race.

8. We may appeal to the coherence of an interpretation or explanation as support for a claim. Someone may say that Lee Harvey Oswald killing JFK is the best explanation, because it covers all the facts and makes sense out of everything.

9. One source of evidence is often anecdotal or personal. A person may decide that a certain store is bad because of a bad experience he or she had, or one that he or she heard about.

Not all of these sources of justification is equal, or is appropriate for every circumstance. The point, then, is that in our search for knowledge, we have many different sorts of evidence that we regard as appropriate for different circumstances. Deciding how to properly support a claim is the process of deciding what kind of justification to choose, and deciding how much of it is needed.