Chapter 4-5 Flashcards
Satisfactory premises
- May require research, calculation, or common sense. Knowing whether or not a given statement is reasonable to believe may require experience and contextual knowledge.
- Expert authority
- common knowledge
- personal testimony
- unverifiable premises
Expert authority
o Premises are generally satisfactory when relevant experts support them.
o The proper authority must be (a) an expert, (b) an expert in the relevant area, (c) honest and reliable (or at least there should not be any reasonable evidence suggesting the contrary), and (d) in agreement with other experts in the area regarding the claim at issue.
¬ Relevant expert: An honest and reliable expert in a given area. A statement that’s the shared opinion of relevant experts is unusually satisfactory when used as a premise in an argument
Personal testimony
o Premises are usually satisfactory when they’re reports based on personal experience. This only applies if the person offering the reports is honest and reliable. At a minimum there should be no evidence to make you doubt that person is honest and reliable.
o Even though a person isn’t lying to you doesn’t mean their report is false, they could be mistaken.
o Personal testimony is satisfactory when the claim made is plausible and restricted to the individual’s personal experience.
Common knowledge
o Some premises are satisfactory because they are common knowledge. Common knowledge and common sense are not the same. Common knowledge doesn’t include unwarranted beliefs and superstitions.
o Common knowledge is just the shared knowledge that is presupposed as background to an argument; any statement that’s commonly known to be true. Dependent on the audience being addressed.
Unverifiable premises
o Arguments in which the truth or falsity of the premises cannot, in principle, be verified. These sorts of concerns raise questions about existence and knowledge.
o Some unverifiable claims are not so obviously satisfactory. Moral claims, are usually difficult or impossible to verify. Statements about what is of value or about what one ought to do are moral claims.
o If statements like these are used ibn premises in arguments, they will not be satisfactory unless some further arguments are provided.
Supporting premises
¬ Questions about satisfactoriness are separate from questions of support. Satisfactory premises can still make a failed argument if they don’t support the conclusion. Support is determined by relevance.
o Relevant premise: A premise that is included in a given argument (or sub-argument) and has bearing on whether the argument’s conclusion should be accepted.
S-test
- Satisfactoriness: Check the satisfactoriness of each premise separately. Is each premise either certainly true or at least reasonable to believe?
- Support: Check whether the premises offer some support for the conclusion. If they are independent premises, look at them all together. If none of the premises offer support, the argument fails step 2 and cannot pass Step 3
- Sufficient support: Check whether, when taken together, the premises supply enough support to justify the conclusion.
A successful argument must pass all three steps. Note that it can be instructive to move on to Steps 2 and 3 of the test. If the premises fail to be satisfactory the argument will not work.
Argument types
Deductive arguments, inductive arguments, arguments from analogy
Deductive arguments
o An argument in which the premises are intended to provide a guarantee of the truth of the conclusion. If the premises are true, the conclusion must be true as well.
Inductive arguments
o An argument in which the premises are intended to provide a high degree of profitability that the conclusion is true. One tries to establish a reasonably high level of profitability.
Arguments from analogy
o An argument that draws a conclusion about one case (called the “primary subject”) on the basis of its similarities to another case (called the “analogue”)
o Draw conclusions about different cases. If the two cases have enough relevant similarities, then our conclusions about one case should apply to the other case as well
o The topic of the conclusion is referred to as the primary subject. An analogue is what the primary subject is being compare to.
Evaluating deductive arguments
o A deductive argument aims to establish its conclusion with certainty. A valid argument is one in which it is impossible for the premises to be true and the conclusion false.
o Satisfactoriness: is there good reason to believe that the premises are true? If not, the argument fails the S-Test and is not sound, but it may still be valid.
o Support: Are there premises relevant to the conclusion? If not, the argument fails the S-Test and can be neither sound nor valid
o Sufficient Support: It is impossible for the premises to be true and the conclusion false? If so, the argument is valid, if not, the argument fails the S-Test and can be neither sound nor valid.
o If it passes all three, the argument is sound.
Evaluating inductive arguments
o These arguments are used for scientific predictions, historical claims, forecasts, and probability assertions, etc.
o Satisfactoriness: is there good reason to believe that the premises are true? If not, the argument fails the S-Test and is weak
o Support: Are the premises relevant to the conclusion? If not the argument fails the S-Test and is weak.
o Sufficient Support: Do the premises offer enough support to justify the strength of the conclusion? If the premises don’t offer enough support, the argument fails the S-Test and is weak
Evaluating arguments from analogy
o Using an argument from analogy involves comparing cases and subsequently drawing a conclusion based upon the strength of the similarities between those cases.
o You must be careful because there are both similarities and dissimilarities between any two items
o Once you’ve determined what the similarities are, you’ll need to determine whether they are relevant to the argument. A strong argument from analogy will have relevant similarities.
S-test for arguments from analogies
o Satisfactoriness: In the case of an indicative analogy, are all the premises factually accurate? In the case of an a priori analogy, you don’t need to evaluate the description of the analogue for the satisfactoriness, but you may still need to evaluate the description of the primary subject. If the support argument fails this step, it’s a bad argument
o Support: Determine which features of the analogue are relevant to the conclusion. Given the context, are there relevant similarities between these features and those of the primary subject? If there are no similarities or if there are only irrelevant similarities, then the argument fails this step of the test and it is a faulty analogy
o Sufficient support: If there are many relevant similarities and few relevant differences, the analogy is strong. The weighting of similarities and differences is highly contextual.
