Basic Concepts 1: Premises and Conclusions

Overview

An argument is a set of reasons or evidence in support of a claim. An argument has two main components: Premises and a conclusion. The conclusion is claim the arguer wants the audience to believe. The premises are reasons and evidence in support of the conclusion. Effectively evaluating an argument begins with being able to identify these two key components.

Critical thinking is NOT a set beliefs. Critical thinking is a systematic method for evaluating arguments, evidence, and reasons. It's very very important that you internalize the idea that critical thinking has very little to do with the content of what you believe and everything to do with why you believe it and how you came to believe it.

Introduction

Suppose you're asked to audit someone's taxes—let's call him George. How would you go about it? One thing you wouldn't do is simply ask George how much he thinks he owes, then make your verdict based solely off of what your gut feeling about that number. Deciding whether he's paying the right amount involves a lot more than simply consulting your intuitions. Strangely, this is how most people evaluate arguments. Depending on whether the conclusion seems right or wrong, they decide whether the argument is good. This is the opposite of critical thinking.

Returning to our accounting example, how would we go about evaluating whether George paid the right amount? We can divide the process into two parts. First, we need to see if he hasn't made any arithmetic errors: Did he add, subtract, divide, and multiply correctly? Broadly speaking, we need to check to see if his mathematical inferences are valid. Suppose it turns out that he didn't make any mathematical errors. Does it follow automatically that George is paying the right amount of tax? Nope. Even if he did all the calculations correctly, it's still possible that he used the wrong numbers in his calculations! For example, suppose his total deductions are the sum of his travel expenses but he forgot to include the receipts from one trip in the total. If he's using the wrong numbers in his calculations, he'll end up with the wrong totals even if he does his math perfectly.

There's an important analogy between thinking about a tax audit and evaluating an argument. When we evaluate arguments we need to check two main things: the logical connections between the parts and whether the parts are "true". In the accounting example, mathematical connection is analogous to logical connection. When we evaluate arguments, logical connection between premises and conclusion is called validity. Evaluating the truth of premises is analogous to verifying whether there's a receipt for each line on the tax return. For any line of a tax return I can challenge its truth and ask for evidence, i.e., for a receipt. Arguments are no different. For each premise, I can ask whether there's evidence that supports the conclusion.

So, why all this talk of tax returns and arguments? Before we can evaluate a tax return we need to know how to do basic math and understand what's supposed to be in each line of the return. The same goes for evaluating arguments. Before we can even begin to evaluate them we need to learn about basic "arithmetic" (i.e., logic) of arguments as well as the various parts that make them up. This whole section is a long way of telling you we're going to have to do what will seem very mechanical for the next four lessons. You'll start wondering, like you did in math class, "when am I going to use this? This is boring!" Trust me, we can't do the evaluation stage (well) until we get some basic skills under our belt. So, if at times parts the next four lessons seem a bit tedious or insignificant you have to trust me that the skills you will learn are essential to doing critical thinking (well).

Defining an Argument

Argument: vas is das? For most of us when we hear the word 'argument' we think of something we'd rather avoid. As it is commonly understood, an argument involves some sort of unpleasant confrontation (well, maybe not always unpleasant—it can feel pretty good when you win!). While this is one notion of 'argument,' it's (generally) not what the term refers to in philosophy.

In philosophy what we mean by argument is a set of reasons offered in support of a claim. An argument, in this narrower sense, also generally implies some sort of structure. For now we'll ignore the structural aspects and focus on the two primary elements that make up an argument: premises and conclusions.

Let's talk about conclusions first because their definition is pretty simple. A conclusion is the final assertion that is supported with evidence and reasons. We can also think of it as the claim that the arguer wants the audience to believe. The relationship between premises and conclusions is important. The premises are independent reasons and evidence that support the conclusion. In an argument, we say that the conclusion should follow from the premises.

Let's consider a simple example:
Claim: Some people thought Miley Cyrus' performance was both a travesty and offensive.

Premise 1: Everyone thought Miley Cyrus' performance was a travesty.
Premise 2: Some people thought her performance was offensive.
Conclusion: Therefore, some people thought her performance was both a travesty and offensive.

Notice that so long as we accept Premise 1 and Premise 2 as true, then we must also accept the conclusion. This is what we mean by "the conclusion 'follows' from the premises."

Let's examine premises a little more closely. A premise is any reason or evidence that supports the conclusion of the argument. In the context of arguments we can use 'reasons', 'evidence', and 'premises' interchangeably. For example, if my conclusion is that dogs are better pets than cats, I might offer the following reasons:

(P1) Dogs are generally more affectionate than cats and
(P2) Dogs are more responsive to their owners' commands than cats.

From my two premises, I infer my conclusion that

(C) Dogs are better pets than cats.

Let's return to the definition of an argument. Notice that in the definition, I've said that arguments are a set of reasons. While this isn't always true, generally a good argument will have more than one premise.

Heuristics for Identifying Premises and Conclusions

Now that we know what each concept is, let's look at how to identify each one as we might encounter them "in nature" (e.g., in an article, in a conversation, in a meme, in a homework exercise, etc…). First, I'll explain each heuristic, then I'll apply them to some examples.

Identifying Conclusions:

The easiest way to go about decomposing arguments is to first try to find the conclusion. This is a good strategy because there is usually only one conclusion so, if we can identify it, it means the rest of the passage is made up of premises. For this reason, most of the heuristics focus on finding the conclusion.

Heuristic 1: Look for the most controversial statement in the argument. The conclusion will generally be the most controversial statement in the argument. If you think about it, this makes sense. Typically arguments proceed by moving from assertions (i.e., premises) the audience agrees to something that the audience might not have previously agreed with.

Heuristic 2: The conclusion is usually a statement that takes a position on an issue. By implication, the premises will be reasons that support the position on the issue (i.e., the conclusion). A good way to apply this heuristic is to ask "what is the arguer trying to get me to believe?". The answer to this question is generally going to be the conclusion.

Heuristic 3: The conclusion is usually (but not always) the first or last statement of the argument.

Heuristic 4: The "because" test. Use this method when you're having trouble figuring which of 2 statements is the conclusion. The "because" test helps you figure out which statement is supporting which. Recall that the premise(s) always supports the conclusion. This method is best explained by using an example. Suppose you encounter an argument that goes something like this:
It's a good idea to eat lots of amazonian jungle fruit. It tastes delicious. Also, lots of facebook posts say that it cures cancer.

Suppose you're having trouble deciding what the conclusion is. You've eliminated "it tastes delicious" as a candidate but you still have to choose between "it's a good idea to eat lots of amazonian jungle fruit" and "lots of facebook posts say that it cures cancer". To use the 'because' test, read one statement after the other but insert the word "because" between the two and see what makes more sense. Let's try the two possibilities:

A: It's a good idea to eat lots of amazonian jungle fruit because lots of facebook posts say that it cures cancer.

B: Lots of facebook posts say that amazonian jungle fruit cures cancer because it's a good idea to eat lots of it.

Which makes more sense? Which is providing support for which?

The answer is A. Lots of facebook posts saying something is a reason (i.e. premise) to believe that it's a good idea to eat amazonian jungle fruit—despite the fact that it's not a very good reason…

Before going any further let's do a comprehension check. Click the link below to try on your own:

Identifying the Premises

Method: Identifying the premises once you've identified the conclusion is cake. Whatever isn't contained in the conclusion is either a premise or "filler" (i.e., not relevant to the argument). We will explore the distinction between filler and relevant premises a bit later, so don't worry about that distinction for now.

Example 1
Gun availability should be regulated. Put simply, if your fellow citizens have easy access to guns, they’re more likely to kill you than if they don’t have access. Interestingly, this turned out to be true not just for the twenty-six developed countries analyzed, but on a State-to-State level too.http://listverse.com/2013/04/21/10-arguments-for-gun-control/

Ok, lets try heuristic #1. What's the most controversial statement? For most Americans, it is probably that "gun availability should be regulated." This is probably the conclusion. Just for fun let's try out the other heuristics.

Heuristic #2 says we should find a statement that takes a position on an issue. Hmmm… the issue seems to be gun control, and "gun availability should be regulated" is taking a position. Both heuristics converge on "gun availability should be regulated."

Heuristic #3 says the conclusion will usually be the first or last statement. Guess what? Same result as the other heuristics.

Heuristic #4.

A: Gun availability should be regulated because people with easy access to guns are more likely to kill you.

Or

B: People with easy access to guns are more likely to kill you because gun availability should be regulated.

A is the winner.

The conclusion in this argument is well established. It follows that what's left over are premises (support for the conclusion):

(P1) If your fellow citizens have easy access to guns, they’re more likely to kill you than if they don’t have access.
(P2) Studies show that P1 is true, not just for the twenty-six developed countries analyzed, but on a State-to-State level too.
(C) Gun availability should be regulated.

Example 2
If you make gun ownership a crime, then only criminals will have guns. This means only “bad” guys would have guns, while good people would by definition be at a disadvantage. Gun control is a bad idea.

Heuristic #1: What's the most controversial statement? Probably "gun control is a bad idea."

Heuristic #2: Which statement takes a position on an issue? "Gun control is a bad idea."

Heuristic #3: "Gun control is a bad idea" is last and also passed heuristic 1 and 2. Probably a good bet as the conclusion.

Heuristic #4:

A: If you make gun ownership a crime, then only criminals will have guns because gun control is a bad idea.

OR

B: Gun control is a bad idea because if you make gun ownership a crime, then only criminals will have guns.

The winner is B, therefore, "gun control is a bad idea" is the conclusion.

All 4 heuristics point to "gun control is a bad idea" as being the conclusion therefore we can safely infer that the other statements are premises:

(P1) If you make gun ownership a crime, then only criminals will have guns.
(P2) This means only “bad” guys would have guns, while good people would by definition be at a disadvantage.
(C) Gun control is a bad idea.

Looking Ahead

Also, many arguments can also contain what are called 'hidden', 'unstated,' or 'assumed' premises.

To understand the notion of a hidden premise let's return to the argument about dogs.

(P1) Dogs are generally more affectionate than cats and
(P2) Dogs are more responsive to their owners' commands than cats.
(C) Dogs are better pets than cats.

Look at (P1). Can you find the hidden premise? Here it is: (HP1) If a pet is more affectionate then it is a better pet than a less affectionate one. This is an assumption that displays the values of the arguer. (Note: hidden premises might not always be about values.)

However, there may be people who don't value affection as a marker of being a good pet. Maybe for some people what makes a good pet is that it is clean or self-reliant. So, a huge part of being a good critical thinker is to look beyond the stated premises and to try to find the assumed premises. When we do this, the task of assessing the relative strength and weaknesses of an argument's premises (and, in turn, the argument itself) becomes much easier.

A cat lover could now counter the dog-as-better-pets argument by showing that the hidden assumption that (P1) relies on isn't necessarily true, and therefore the conclusion doesn't necessarily follow.

So, the cat lover can show that (C) (dogs are better than cats) doesn't necessarily follow from (P1) (dogs are more affectionate than cats) because (P1) is only supports the conclusion if we also assume that affection-giving is an important determinant of being a good pet. In other words, the dog proponent's argument only works if we also accept their hidden assumption/premise.

However, showing that (C) doesn't follow from (P1) doesn't mean (C) is false, nor does it show the contrary, that cats are better pets than dogs. It only shows that "dogs are better pets than cats" can't be established through this particular argument or at least not without further argument.

In other words, it could very well be true that dogs are better pets than cats but this argument doesn't show it. In order to prove that dogs are better than cats we'd need a different argument or support for the hidden premise.

This brings us to an interesting point which I'll discuss in the next section: systems of belief, biases, and values. When (as often happens) arguments involve values, evaluating an argument as 'true' or 'false' becomes difficult because it is an open question whether a value (that is supporting a major premise or conclusion) can be 'right' or 'wrong'.

This is more a question for ethics, but as far as being good critical thinkers goes, it is extremely important to be able to recognize when and how a premise or conclusion is ultimately supported by a value judgement, bias, or system of belief.

The next post will give an overview of systems of belief, biases, and values, and their role in arguments and critical thinking.

Summary

An argument is a set of reasons or evidence offered in support of a claim.

A premise is an individual reason or piece of evidence offered in support of a conclusion.

A conclusion is the claim that follows from or is supported by the premise(s).

Key ideas:
1) Just because a conclusion is true, it doesn't mean that the argument in support of the conclusion is a good one (i.e. valid). Truth and justification are two different things!

2) Be on the alert for hidden premises!

Self-Quiz

Examples of Simple Arguments

Examples from BroScience

Examples from Ethics

1. One should always do that which creates the greatest amount of pleasure for the greatest number because happiness is the most important value. It's the most important value because it's what everyone desires most.

Animal Ethics
1. An animal is euthanized every 11 seconds in the United states. By the time you've read these words, another innocent animal has lost it's [sic] life. Spay and neuter!

2. Anyone thinking of getting a puppy should do their research on puppy mills before they buy from a pet shop, the Internet, or a breeder. Remember the parents of those cute puppies live in hell for their entire lives!

Examples from History

1. In the war of 1812 Canadian troops burned the White House to the ground. That's why Americans shouldn't start any shit with Canada.

Examples from Health and Nutrition

Examples from Life Advice

1. Never apologize for being sensitive or emotional. It's a sign that you have a big heart, and that you aren't afraid to let others see it. Showing your emotions is a sign of strength.

2. Don't wait for things to get easier, simpler, better. Life will always be complicated. Learn to be happy right now. Otherwise, you'll run out of time.

3. Be good to your nieces and nephews. One day you'll need them to smuggle alcohol into your nursing home!

Examples from Mommy Ph.D

Examples from Movies

Examples from Music

Examples from Philosophy

Examples from Politics and Policy

1. Stiglitz argues for imposing a land value tax, to directly address this source of increasing wealth inequality. Economists have long favored such a tax, because it does little or nothing to distort incentives: Since land is roughly fixed in supply, there's little one can do to escape a land tax. Indeed, from the perspective of economic efficiency, a land value tax scores higher than even a value-added tax, which is typically seen as the most efficient form of taxation. https://www.bloomberg.com/view/articles/2015-03-03/to-fight-inequality-tax-land

2. "Yes I know the guy I'm seeing is a rapist but what am I supposed to do - stop dating!?" This is literally what you sound like when you say you voted for the lesser evil. (You'll need to infer the implied conclusion).

3. The whole thing [election] is rigged. The DNC didn't want Bernie to win regardless. Look at every state that had voter suppression. They don't care about what the majority of the people want.

4. In Finland, some traffic fines, as well as fines for shoplifting and violating securities-exchange laws, are assessed based on earnings. But to advocate for the American adoption of day-fines isn’t to engage in the standard grass-is-greener worship of Scandinavia that’s in style right now. It’s logical. Yes, day-fines might dissuade the rich from breaking the law; after all, wealthier people have been shown to drive more recklessly than those who make less money, and Steve Jobs was known to park in handicapped spots and drive around without license plates. But more importantly, day-fines could introduce some fairness to a legal system that many have convincingly shown to be biased against the poor.1

Examples from School Life

1. We won't take attendance tomorrow because it's the first day. Also, John won't be there. Besides it wouldn't be fair to enforce a rule unless students know the rule first.

Examples from Science

1. Moving genes from one kind of organism to another (horizontal gene transfer) occurs frequently in nature. For example, humans have about 150 identified genes of viral origin in their genomes, and Amborella, a peculiar flowering plant from New Caledonia that has more ancient features than any other, has about 40 such extraneous genes documented to have come from three different kingdoms. So it’s not in any way “unnatural” for horizontal gene transfer to occur. http://www.forbes.com/sites/gmoanswers/2016/08/19/gmo-scientific-progress/#ab12d202d9d6

Examples from Sports

1. Nick Diaz should have won the fight against MacGregor. For 3 of the 5 rounds Diaz controlled MacGregor against the fence. He also probably landed more shots. Besides, even if MacGregor won the 1st round, it wasn't a 10-8 round.

2. Conor won that fight 3-2. You may have scored that fight for Diaz if you listened to Rogan, but the best way to judge a fight is to watch it without audio. Do it. Accept it. This was a fair decision. I look forward to the next one.

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