Argument Basics

Defined

While people generally think of an argument as a fight, perhaps involving the hurling of small appliances, this is not the case-at least as the term is used in philosophy. In philosophy, an argument is a set of claims, one of which is supposed to be supported by the others. There are two types of claims in an argument. The first type of claim is the conclusion. This is the claim that is supposed to be supported by the premises. A single argument has one and only one conclusion, although the conclusion of one argument can be used as a premise in another argument (thus forming an extended argument).

The second type of claim is the premise. A premise is a claim given as evidence or a reason for accepting the conclusion. Aside from practical concerns, there is no limit to the number of premises in a single argument.

Varieties

   There are two main categories of arguments, three if bad arguments are considered a category. The first type is the inductive arguments. An inductive argument is an argument in which the premises are intended to provide some degree of support but less than complete support for the conclusion.

The second type is the deductive argument. A deductive argument is an argument in which the premises are intended to provide complete support for the conclusion.

The third “type” of argument is the fallacy. A fallacy is an argument in which the premises fail to provide adequate support for the conclusion.

Examples

Inductive Argument
Premise 1: When exposed to the nerve argent known as “Rage”, the chimpanzees showed a massive increase in aggression.

Premise 2: Humans are very similar to chimpanzees.

Conclusion: If exposed to “Rage”, humans would show a massive increase in aggression.

Deductive Argument

Premise 1: If pornography has a detrimental effect on one’s character, it would be best to avoid it.

Premise 2: Pornography has a detrimental effect on one’s character.

Conclusion: It would be best to avoid pornography.

Extended Deductive Argument

Argument1, Premise 1: If pornography has a detrimental effect on one’s character, it would be best to regard it as harmful.

Argument 1, Premise 2: Pornography has a detrimental effect on one’s character.

Argument 1, Conclusion: It would be best to regard pornography as harmful.

Argument 2, Premise 1: If it is best to regard something as harmful, then the government should protect people from it.

Argument 2, Premise 2: It would be best to regard pornography as harmful.

Argument 3, Conclusion: The government should protect people from pornography.

Fallacy

Premise 1: Dave supports the tax reduction for businesses and says it will be good for everyone, but he owns a business.

Conclusion: Dave must be wrong about the tax reduction.

General Assessment

When assessing any argument there are two main factors to consider: the quality of the premises and the quality of the reasoning.

While people often blend the two together, the quality of the reasoning is quite distinct from the quality of the premises. Just as it is possible to build poorly using excellent materials, it is possible to reason badly using good premises. Also, just as it is possible for a skilled builder to assemble crappy material with great skill, it is possible to reason well using poor premises. As another analogy, consider a check book. Doing the math is the same thing as reasoning. The math can be done correctly (good reasoning) but the information entered for the checks (the premises) can be mistaken (for example, entering $5.00 instead of $50). It is also possible to enter all the check correctly, but for there to be errors in the mathematics.

Reasoning

When assessing the quality of reasoning, the question to ask is: Do the premises logically support the conclusion? If the premises do not logically support the conclusion, then the argument is flawed and the conclusion should not be accepted based on the premises provided. The conclusion may, in fact, be true, but a flawed argument gives you no logical reason to believe the conclusion because of the argument in question. Hence, it would be a mistake to accept it for those reasons. If the premises do logically support the conclusion, then you would have a good reason to accept the conclusion, on the assumption that the premises are true or at least plausible.

The way the reasoning is assessed depends on whether the argument is deductive or inductive. If the argument is deductive, it is assessed in terms of being valid or invalid. A valid argument is such that if the premises were true then the conclusion must be true. An invalid argument is such that all the premises could be true and the conclusion false at the same time. Validity is tested by formal means, such as truth tables, Venn diagrams and proofs.

If the argument is inductive, it is assessed in terms of being strong or weak. A strong argument is such that if the premises were true, then the conclusion is likely to be true. A weak argument is such that if the premises were true, then the conclusion is not likely to be true. Inductive arguments are assessed primarily in terms of standards specific to the argument in question.

Premises

When assessing the quality of the premises, the question to ask is: are the premises true (or at least plausible)? While the testing of premises can be a rather extensive matter, it is reasonable to accept a premise as plausible if it meets three conditions. First, the premise is consistent with your own observations. Second, the premise is consistent with your background beliefs and experience. Third, the premise is consistent with credible sources, such as experts, standard references and text books. It should be noted that thoroughly and rigorously examining premises can involve going far beyond the three basic standards presented here.

Introduction to Inductive Arguments

Defined

An inductive argument is an argument in which the premises are intended to provide some degree of support, but less than complete support, for the conclusion. In other words, the premises are offered as evidence that the conclusion is likely to be true. This distinguishes them from deductive arguments-they are arguments such that the premises are supposed to provide complete support for the conclusion.

The conclusion of an inductive argument goes beyond the evidence presented in the premises-this is what is known as the inductive leap. A clear example of the leap can be shown by using a basic inductive argument-a generalization of the sort used in surveys. Suppose Bill wants to know what the students in his history class think about a rule that forbids freshmen from parking on campus. He asks twenty students out of the fifty enrolled and 70% of them agree with the rule. If he concludes that 70% of all the students agree with the rule, he is making a leap from what he has observed (the students he questioned) to what he has not observed (the remaining students).

This example also shows why the premises of an inductive argument do not provide complete support for the conclusion. After all, even if it is true that 70% of those asked agree with the rule, Bill cannot be certain that the same is true of those he did not ask. Perhaps many of the thirty students he did not question are freshmen and thus likely to disagree with the rule.

Assessment

Like any argument, inductive arguments are assessed in terms of how strongly the premises support the conclusion. Inductive arguments are generally presented as specific types, such as analogical arguments or generalizations. These arguments are also assessed by standards specific to their type. For example, an analogical argument is assessed in terms of the quality of the analogy.

Strong and Weak Arguments

While deductive arguments are assessed in strict “black and white” terms (valid or invalid, sound or unsound), inductive arguments are assessed in terms of varying degrees of strength.