Philosophy isn’t just a form of creative writing. It’s an attempt to use good reasoning, and writing good philosophical arguments requires an understanding of good reasoning. Most people have an intuitive grasp of what “good reasoning” is, but this intuitive grasp is often insufficient. Our reasoning can be improved from experience and philosophy education. I will discuss three steps of writing good philosophical arguments:
- Make your argument explicit.
- Consider the evidence for your argument.
- Consider relevant objections and rebuttals.
1. Make your argument explicit
There are two main types of arguments—positive and negative. Positive arguments argue for a belief, and negative arguments (objections) argue against a belief. Either way, we need to make it clear what the premises and conclusion of our argument are.
Imagine that Jill wants to argue that capital punishment is wrong in our current time period. She will need to know why she personally thinks capital punishment is wrong and why anyone should agree with her. The first thought that might come to mind is that human life has value. At this point her argument is the following:
- Human life has value.
- Therefore, capital punishment is wrong.
This argument might look good enough, but it’s technically invalid. The argument form is “A, therefore B” and arguments using this form of reasoning can have a true premise and false conclusion. For example, “the sky is blue, therefore there is no oxygen in the air” has the same argument form, but it’s clearly a poor argument.
Find unstated assumptions
The reason why the argument might look like a good argument is because we might have unstated assumptions. For example, we might think that human life’s value makes it wrong to kill people, and capital punishment is an example of killing people. This assumption is not something everyone will agree with. Many people think we can occasionally be morally justified to kill people, such as when it’s necessary to defend our lives. Even so, we should make sure to have all the necessary assumptions to be stated as premises. The argument will then look like the following:
- Human life has value.
- If human life has value, then capital punishment is wrong.
- Therefore, capital punishment is wrong.
This argument is now valid because it uses the valid argument form known as modus ponens (A; if A, B; therefore B).
There are two main kinds of objections in philosophy—objections to arguments and objections to conclusions. When objecting to arguments, we must make the premise that we object to explicit. When we object to conclusions, it is often also necessary to object to arguments as well.
Consider that someone has the following argument for capital punishment:
- Evil people deserve to die.
- If evil people deserve to die, then capital punishment is morally justified when used to kill evil people.
- Therefore, capital punishment is morally justified when used to kill evil people.
This argument is incompatible with Jill’s belief that capital punishment is morally wrong. She can object to both the argument and the conclusion.
Objections to arguments
If we want to object to the argument, then we can either object to the reasoning used or a premise. The reasoning used by philosophy professors tends to be pretty good, but the evidence for the premises is often lacking. In the case of the above argument for capital punishment, no obvious poor reasoning is being used and the argument is logically valid. However, we might wonder if the premises are sufficiently justified. (I didn’t actually present any evidence for any of the premises, but an actual philosophical argument would be likely to do so.)
We might object to the premise that “evil people deserve to die.” This premise might be impractical if no one is evil or if we have no way of knowing who is evil. Additionally, it’s not obvious that evil people deserve to die. It might be that even evil human life has value. Objections to premises tend to use the following reasoning:
- A certain premise is unjustified.
- If the premise is unjustified, then the argument can’t give us reason to accept the conclusion.
- Therefore, the argument doesn’t give us reason to accept the conclusion.
For example, Jill can object to Argument 2 using the following objection:
- The argument in question requires us to accept that “evil people deserve to die,” but that premise is unjustified (because evil people might have value like everyone else, etc.).
- If we aren’t justified to accept that “evil people deserve to die,” then the argument doesn’t give us reason to accept the conclusion—that “capital punishment is morally justified when used to kill evil people.”
- Therefore, the argument doesn’t provide sufficient justification to conclude that “capital punishment is morally justified when used to kill evil people.”
Notice that she didn’t claim that the conclusion is false. If a premise of an argument is unjustified (or false), that doesn’t prove that the conclusion is false. There could be a different argument that proves the conclusion to be true. For example, it might be that capital punishment is justified when we can’t throw a dangerous criminal in prison as a form of self-defense.
How do we object to forms of reasoning? Many people use poor forms of reasoning. In that case it can be helpful to identify either that the argument uses a formal fallacy (an invalid form of reasoning) or an informal fallacy (some other mistake in reasoning). Once the poor reasoning is identified, we can explain it and present a counterexample.
Consider an example of a formal fallacy and counterexample. – A person can argue that “if dogs exist, then they have four legs; dogs have four legs; therefore dogs exist.” The premises and conclusion are all true, but it’s still a poorly reasoned argument because the same reasoning could be used to prove things that are false. We can then give a counterexample that shows how we can use this form of reasoning and true premises, but a false conclusion—“If unicorns exist, then they have four legs; unicorns have four legs; therefore unicorns exist.” It is true by definition that unicorns would have four legs if they exist, and that “all unicorns have four legs” as a result, but it’s false that unicorns exist.
Consider an example of an informal fallacy and counterexample. – A person can argue that “capital punishment is wrong because it’s always wrong to kill people. Consider how it’s wrong to go around killing people who make us angry, annoy us, and so on.” This seems like an example of a “hasty generalization.” It seems like quite a leap to think it’s always wrong to kill people. We could then give a counterexample making use of hasty generalizations—“It is wrong to cut people because it’s always wrong to hurt people. Consider how it’s wrong to go cutting people with knives who make us angry, annoy us, and so on.” However, we know it’s false that it’s always wrong to cut people because surgeons cut people and hurt them as a result, but only do so because it’s necessary to heal people. This is a counterexample insofar as it shows how a hasty generalization is one context is an example of poor reasoning and it’s wrong in other contexts for the same reason.
How do we object to conclusions? In philosophy, objections are almost always expected to be against arguments rather than merely against conclusions because it’s not usually obvious how successful arguments are that only object to a conclusion. In that case one argument attempts to prove the conclusion is true, but another attempts to prove it’s false. We would then need a way to decide which argument is better. Nonetheless, it is important for strong objections to be given against both premises and conclusions because that’s the only way we can truly prove a conclusion to be implausible.
We can object to a conclusion using a reduction to absurdity and counterexamples. We can assume the conclusion is true and show that such an assumption leads to a contradiction—either from internal inconsistency or because it conflicts with our knowledge.
Consider an example of a belief that lacks internal consistency. – Someone could argue that “all opinions are equally justified.” We could object that this belief would imply that the opinion that “not all opinions are equally justified” is a viable option, but that means we have no reason to agree that “all opinions are equally justified.”
Consider an example of a belief that conflicts with our knowledge. – Someone could argue that “we don’t know anything,” but we can object that such a belief would imply that we don’t know that “1+1=2” even though we do know that. The fact that we know “1+1=2” is a counterexample to the belief that we don’t know anything.
2. Consider the evidence for your argument.
It’s not enough for a philosophical argument to state our argument explicitly because our premises could be unjustified. We need to know why anyone would agree with our premises, and consider why we think the premises are probably true. We must find a way to present our evidence to people to support our premises in order to be assured that we have a good argument, and we must make sure that the premises really do prove our conclusion to be true.
Consider Argument 1. It requires us to accept that “human life has value” and “if human life has value, then capital punishment is false.” There are people who will reject these premises, so they can’t just be assumed to be “obviously true.” We need to defend the premises and decide how plausible they are.
In this case Jill will justify her premises in the following ways:
- Human life has value. – Jill will find this belief intuitive because she seems to experience her own life to be valuable and she realizes that other people do as well. She can defend that we share her intuition that human life has value in at least two ways. One, it would seem strange to want people to commit suicide just because they are in pain. Two, we think it’s generally wrong to kill people, and we find people who kill others without a justification to have done something morally wrong. One explanation to why it’s generally wrong to kill people is that human life has value. She can then consider alternative explanations and try to show why they are less plausible than her suggestion. For example, some people might argue that we only think it’s wrong to kill people because we care about them, but Jill could either argue (a) caring about people is merely one understanding of what it means for human life to have value or (b) that it seems inappropriate when people don’t care about others (such as strangers), and there are many cases when people harm strangers because they don’t care enough about them.
- If human life has value, then capital punishment is wrong. – Jill will find this intuitive because she thinks the fact that something has value is a reason not to destroy it. We think happiness is valuable, so we usually shouldn’t try to make people miserable, and it would often be morally wrong to do so. The same seems to be true of the value of human life. The two cases seem analogous. We have a reason not to destroy happiness if it has value, and we have a similar reason not to destroy human life if it has value. It’s often morally wrong to destroy happiness if it has value, and it’s often morally wrong to destroy human life if it has value. This still doesn’t prove that capital punishment is wrong. Jill can then argue that there is no moral justification for capital punishment (at least in the society she lives in). It’s wrong to kill people unless we have a good reason to do so, and there’s no good reason to kill criminals who are safely in custody. She can consider various justifications for capital punishment and try to show them to be unsatisfying. For example, someone could argue that capital punishment makes the family of murder victims feel better, but Jill could argue that the good feelings people get from the death of others is never a good reason to kill anyone. Many murderers get a good feeling from killing others, but that doesn’t excuse their behavior.
We need to make sure that our conclusion is proven.
The plausibility of the conclusion depends on the plausibility of the premises. We could have premises and conclusions that are justified to the following degrees:
- The premises can be intuitive, but we can admit that there could be alternative beliefs that are equally plausible. In that case the conclusion wouldn’t be proven to be true. Instead, it would merely be compatible with intuitive beliefs.
- Rejecting the premises could be “counterintuitive.” In that case rejecting the conclusion would require us to accept counterintuitive beliefs.
- There’s some reason to believe the premises, but we can admit that there could be overriding reason to reject them that haven’t been discovered yet.
- The premises could be the most likely option. Perhaps they are the “best explanation” for our experiences. In that case the conclusion would be based on the most likely options, but it might be unclear if the conclusion is probably true.
- The premises could be probably true. In that case the conclusion would also be probably true.
- The premises could be a rational requirement, and everyone should agree with them. In that case the conclusion would also be a rational requirement because rejecting the conclusion would require us to reject rationally required beliefs.
I will discuss each of these possibilities:
1. Premises can be intuitive
Premises are only intuitive if we have no strong reason to reject them. Such beliefs are “initially plausible.” Many of our beliefs are merely assumptions that we find successful and coherent rather than something everyone has to accept. Also note that two incompatible beliefs could both be intuitive. It might be intuitive to think that killing people is usually wrong because human life has value, but it might be equally intuitive to think that killing people is usually wrong because it goes against a “social contract.”
In that case premise 1 (human life has value) might not even be necessary for Jill’s argument because there could be more than one reason to think that killing people is wrong unless we have a good justification for doing so. Jill could change premise 1 to be “killing people is wrong unless we have an overriding reason to do it” and explain how there’s more than one plausible explanation for this premise.
One reason to argue that a belief is intuitive is to show that it seems rational to hold the belief. If an argument uses intuitive premises, then the conclusion doesn’t require us to accept anything irrational, and that makes it more plausible that the conclusion can be rationally held. However, there might be exceptions. An argument that uses intuitive premises should not lead to a conclusion that many people will find counterintuitive or far-fetched. If initially intuitive premises lead us to a counterintuitive conclusion, then the premises will be proven to be less intuitive than we thought they were. For example, the fact that many people expect heavy objects to fall faster than less heavy ones conflicts with our observations, so such an initially intuitive belief should be rejected based on more reliable conflicting information. We can’t rationally accept the “intuitive belief” because it would require us to reject scientific observations.
2. It can be counterintuitive to reject the premises.
If it’s counterintuive to reject a belief, then the belief seems to be strongly intuitive, and the other options are not equally intuitive. We can use an argument from absurdity and “counterexamples” to reveal that rejecting a belief is counterintuitive. The argument from absurdity requires us to assume that our belief is false, and then we can show why such an assumption leads to absurd results. For example, the belief that killing people is wrong unless we have an overriding reason to do so seems intuitive and rejecting it seems counterintuitive. (There could be overriding reasons to kill people, such as when it’s necessary to survive while fighting in self-defense.) Let’s assume that killing people isn’t wrong when people lack an overriding reason to kill. In that case people could kill others indiscriminately. It would never be wrong to kill people. However, this leads to an absurdity because we know killing is often wrong, such as when a thief kills a family to steal their money out of greed.
Whenever rejecting beliefs is counterintuitive, we have found some support to the idea that it’s rational to accept the beliefs (because rejecting them seems to lead to absurdity). Such beliefs could generally be said to be strongly intuitive. However, if such “strongly intuitive” beliefs lead us to a counterintuitive or far-fetched conclusion, then the argument loses credibility because we won’t be sure if the premises should be accepted after all. If it’s inevitable for some of our beliefs to be counterintuitive, then the fact that a belief is counterintuitive isn’t necessarily a good reason to reject it. For example, much we have learned in quantum mechanics is counterintuitive and we have no choice but to accept the counterintuitive results. For example, quantum mechanics reveals that situations can occur analogous to the Schrödinger’s cat thought experiment—a cat in a closed box can be both dead and alive until we open it. Once we open the box to take a look, the cat will be either dead or alive instead (without the possibility of being both). In a similar way a photon can be both a particle and a wave when we don’t observe it, but it will either be a particle or a wave while we observe it (without the possibility of being both).
3. There can be some reason to accept the premises.
Many arguments are in favor of a belief without necessarily sufficiently proving the belief to be true. In fact, most philosophical arguments fail to convince everyone and many philosophical debates have lasted thousands of years. For this reason many philosophers merely argue that they provide some reason in favor of a belief rather than sufficient reason to accept a belief. For example, the fact that capital punishment kills a person seems like a good reason to think it’s wrong, even though there could be an overriding reasons to think capital punishment isn’t always wrong.
4. Premises can be more justified than the alternatives.
When philosophers present arguments to explain why we have some reason to believe something, they could present their evidence in isolation from other perspectives and arguments. However, that’s not usually how philosophers argue. Instead, philosophers tend to try to show how we have some reason to accept a belief as well as some reason to reject the alternatives. One of the most persuasive forms of philosophical argumentation will attempt to show why a belief is more plausible than the alternatives in an attempt to present all viable sides of a debate. This can be done by contrasting the most viable options we have and showing why one belief in particular is the best (at least when considering various objections and counterevidence).
Note that one belief that is more viable than the alternatives is not necessarily likely to be true. There could be many viable options that are all plausible. For example, at one point there were many competing versions of string theory in physics and there was no reason to find any of them to be particularly likely to be true. There could be three theories and they could all be around 33% likely of being true. In that case they are each individually more likely false than true.
Consider that Jill’s argument that capital punishment is wrong is inconclusive and only provides us some reason to agree that capital punishment is wrong. Jill could strengthen her argument by considering arguments in favor of capital punishment and try to show them to be flawed. She could then contrast her belief that capital punishment is wrong with the opposing belief that capital punishment isn’t wrong. For example, her objection to the view that capital punishment is justified to make a victim’s family feel better seems to show how it’s a poor excuse for killing a person. Jill could then argue that on the basis of various considerations, we have more reason to think capital punishment is wrong than right. At the same time she should admit that she is giving us reason to think capital punishment is wrong without providing sufficient proof. There could be relevant arguments and objections she didn’t think of.
5. Premises can be probably true.
Philosophers are rarely confident to the point of thinking they proved something to be probably true or accurate, but there many beliefs we have that we agree fits this status. For example, it’s probably true that “killing people is often morally wrong.” We might even suspect that it’s a rational requirement to agree with that statement.
6. Premises can be rational requirements.
The strongest justification for beliefs can show that we know they are true for certain, and some philosophers think some beliefs fit this description, such as our belief that “1+1=2.” However, even beliefs that are rationally required are not necessarily known for certain. It seems that we are rationally required to believe many facts concerning logic, mathematics, and the natural world. It seems plausible to say that we are rationally required to believe that “something can’t be true and false in the same respect at the same time” and that “at least one person has a mind.” Some of the best conclusions involving rational requirements in philosophy involves irrational beliefs and failures in reasoning. Philosophers have cataloged several logical fallacies (poor forms of reasoning) and have discovered many beliefs to be unjustified based on poor reasoning. For example, the beliefs that “nothing is morally wrong” and “all opinions are equal” are unjustified beliefs based on poor reasoning.
Amateurs and non-philosophers often make the mistake of asserting that they know something is true or that something is proven despite the fact that what they are saying is based on imperfect reasoning and evidence. Controversial beliefs are rarely known to be true for certain and are rarely proven to be true. These non-philosophers might think “everyone should agree” with their belief and they might even think people are rationally required to agree. However, philosophical arguments aren’t just examples of creative writing. Philosophers must be honest and aware of what their arguments prove, and they must not exaggerate their conclusions.
If you aren’t sure how strong your argument is, you can merely say that you want to prove it’s intuitive and/or that you want to present some amount of reason in favor of a position. If you are objecting to an argument, you can make it clear that you are merely challenging that argument, providing reason to find a premise to be unjustified, and that the argument seems to fail to prove the conclusion as a result.
Once Jill evaluates Argument 1 and her justification for that argument, she can rephrase her argument in the following way:
- It’s counterintuitive to deny that “it’s wrong to kill people without an overriding reason to do so” (because that would imply that indiscriminate killing isn’t wrong).
- The belief that “if it’s wrong to kill people without an overriding reason to do so, then capital punishment is wrong in our society” is more plausible than the alternatives (because it’s unclear how we can have an overriding reason to have capital punishment in our society).
- Therefore, we have some reason to agree that “capital punishment is wrong in our society.”
3. Consider relevant objections and rebuttals.
One way philosophers tend to strengthen their arguments and make them less one-sided is to consider objections to their arguments, and attempt to dispel the objections by replying to them. Replies to objections are usually also arguments known as “rebuttals” or “counterarguments.”
Consider Argument 1B and Jill’s justifications for her argument. Jill’s second premise should already take objections into consideration because she should argue that reasons to have capital punishment aren’t good, so there’s no overriding reason to kill our criminals in our society. She should argue that revenge, making people feel good, and the idea that evil people deserve to die are all insufficient reasons to kill criminals. However, there could still be more objections worth discussing. In particular, there could be objections given to premise 1. Some people might object that they don’t share the relevant intuitions and that we should accept that “nothing is morally wrong.” Jill could then reply that either she personally would prefer to live under a social contract that forbids people from killing each other, or she could examine more evidence that could explain how we know that killing people is usually wrong. For example, she could discuss her belief that human life has value and argue that this is the best explanation of widespread acceptance that “killing people is usually wrong.”
Most arguments people create are missing premises, rely on unstated assumptions, lack sufficient evidence to reach their conclusions, the conclusions are arrogantly assumed to be proven, and they fail to take objections into consideration. Most objections people create against arguments are vague and fail to disprove the conclusions of the arguments they oppose because they rarely consider the plausibility of the premises, conclusions, and form of reasoning used. Nonetheless, experience and careful thought can lead to improved reasoning. Philosophers sometimes make the same mistakes in reasoning as everyone else, but they are interested in improving their behavior and learning from their mistakes.