If Philosophy is every question and answer regarding the nature of existence, then logic is the way in which we give those questions and answers structure. Logic does not tell us whether an answer is correct or incorrect, but it does allow every person to come to the same conclusion based on a given foundation. It provides clarity and uniformity. The foundation assumptions on which a logical argument is built are called axioms or first principles. A logical argument has a flow to it. Each argument is a consequence of the previous argument up until reaching the fundamental axioms.
Note that axioms are not known to be true. They are assumed to be true for the sake of argument. Individuals who use a different set of axioms are not necessarily wrong. However, discussions become rather problematic when two people hold different axioms to be true, especially if those axioms are contradictory.
The flow of a logical argument is controlled by logical consequence. If we say A implies B, then if we have A to be true, B must also be true. This does not mean that A must be true. In most logical frameworks, a statement is either true or false. This works even in the real world. The issue isn’t the invalidity of a true/false dichotomy, but rather in the use of poorly defined. Since natural languages are highly ambiguous, it’s often dicult to tell whether or not a statement is true or false. Another common snag is using logical arguments that do not follow from fundamental axioms. There are two general forms of logical reasoning: deductive reasoning and inductive reasoning. They are different methods of drawing conclusions from a corpus of information and both are equally important.
A formal fallacy is one that specifically contradicts a logical argument. If we say A implies B, then assuming A and saying not B would be a formal fallacy. These fallacies are very destructive to an argument, but they are at least rather easy to identify. Unfortunately even with their identification, it’s not always easy to get passed the block in the discussion. People will often demand that the logical error is indeed valid in order to continue to “prove” a point.
A non-sequitur, from the Latin meaning “does not follow” is a formal logical error in which a conclusion does not immediately follow from a given set of premises and logical consequences.
Information fallacies are probably one of the most common type of fallacy. These fallacies either fail to use a logical argument at all or rely on false assertions. Some examples of informal fallacies could arise in political discussions and in discussions in general are the ad hominem argument, appeal to authority, begging the question, red herrings, straw man arguments, or the fallacy fallacy. One of the difficulties regarding such fallacies is that many statements end up being multiple fallacies. For instance, trying to explain one fallacy may turn into a red herring, leading the discussion off course.
An ad hominem argument is one that attacks a person’s character in order to declare a position invalid. One common ad hominen used in political discussions is that the constitution is invalid because the people who wrote it were aristocratic white men who owned slaved. While this characterization of the founders might not be 100% false, it holds no relevance in determining their ability to draft a functioning constitution.
Another type of ad hominem would be the attack of how people use an idea. For instance, both abortion and intelligent design are often attacked based on those who have supported the idea. Abortion is attacked because Margaret Sanger had the intention of using abortion as part of her eugenics campaign, while intelligent design is often attacked as a means through which Christians can express their religious ideas in a classroom environment.
A personal attack is not always an ad hominem. If the attack is not used to actually undermine an argument, then it is not an ad homimen. It is just an insult.
Appeal to Authority
Argumentum ad verecundiam or appeal to authority may or may not end up being a logical fallacy depending on how it is used. The assertion made is that the source of information is a valid one and that therefore the information is most likely to be correct. In other words, citing Michio Kaku when having a discussion on gravity is a reasonable action, since Kaku has peer reviewed work published on the material. Likewise, citing evolutionary psychologists when supporting discussions on human behavior is acceptable because these people are presumed to be experts in the field: they have done the work necessary to suggest that their answers are likely to be valid.
The fallacy comes into play when the source is not actually an expert. For instance, spending two years overseas does not make someone an expert on foreign affairs. While not generally discussed as its own fallacy, considering someone an expert due to age alone is also a form of appeal to authority that produces a fallacy.
Begging the question
Begging the question is basically circular reasoning. Begging the question starts by assuming an unproven result. Through a series of logical consequences fol- lowing this assumption, the original assumption is then “proven” to be true. However, since the proof relies on the initial assumption, it is an invalid proof.
If you happen to remember ‘A Pup Named Scooby-Doo’ then you might already have an idea of what a red herring is. Essentially, a red herring is any point that acts to throw the conversation into a new direction and away from the desired result.
Straw Man Argument
In the case of a straw man, an argument is established such that it can easily be torn down. This result is then used as justification as to why the original argument can also be torn down.
This one might sound a little silly, but it is an important fallacy. Just because someone uses a logical fallacy to justify his or her claim does not mean that the claim itself is false. Therefore asserting a claim to be false simply because it was justified using a logical fallacy is in and of itself a logical fallacy.
False dilemma occurs quite frequently in political discussions, especially if a libertarian or other third party voter is involved. False dilemma incorrectly asserts that there are only two options for a given situation. For instance, one might argue that a libertarian is a Republican because he is not a Democrat. However, those are not the only two options.
There are many other fallacies. To further complicate issues, many errors in logic actually constitute examples of multiple fallacies. Straw men often turn into red herrings, for instance. However, by understanding these basic fallacies, one’s own argument can be strengthened.
Regarding pointing out errors in others, it is best to avoid using any label for the fallacy, unless you are having a discussion with someone who is well versed on the topic and is willing to listen. Otherwise simply try to point out the specific error and move on.
There are two categories of logical razors: statements of probability and protocol. I will address probability in detail in later sections, but for now, let me give some examples of commonly used razors: Occam’s razor, Newton’s flaming laser sword, Popper’s falsifiability principle, Hanlon’z razor, and Hitchen’s razor.
Occam’s razor is probably one of the most well known razors. It simply states that when given multiple possible explanations, it makes sense to start with the most simple explanation: usually the one with the least assumptions. In the some cases, the most simple explanation is indeed the correct one, though it may not need be. Occam’s razor is used both in philosophical discussion as well as in creating models of real life events.
There is an issue with Occam’s razor, which I did not mention when I first started writing this text. While Occam’s razor is very useful in certain situations, it is not something which holds in general (Why The Simplest Theory Is Never The Right One: Occam’s Razor Has A Double Edge). For one thing, in many cases, one can restate two positions, such that the one which was originally more complex becomes less complex. Thus there is an ambiguity in complexity of such positions. Often syntactic simplicity is used as our metric.
So when does Occam’s razor work? It is useful in terms of prediction. A model which is more complex, is less likely to be a useful predictor, sometimes even if it is a more precise model. As such, we select the model which is “simpler.” Unfortunately while Occam’s razor is incredibly well formalized within model fitting, it often used beyond its limitations to select one model over another (The Role of Occam’s Razor in Knowledge Discovery).
Newton’s Flaming Laser Sword
Newton’s flaming laser sword is a concept stated by Mike Alder, mathematician University of Western Australia. Basically it states if something can not be settled through experimentation then don’t bother wasting time on it. This razor is rather specific to scientists. Pure philosophers would probably disagree with this assertion. Personally I think that it’s too harsh a statement. Later on I will discuss specific concepts of science and how science differs from general philosophy, but I will say that science is still philosophy.
What we probably should really avoid, rather than asking questions that can not be settled through experimentation, is confusing those that can be with those that can not be. If we’re discussing philosophy from an unscientific point of view, we should not be injecting science into the puzzle, nor should we inject unscientific points of view into science. There are however exceptions: the boundary between science and how science affects us. For instance, “is it ethical to use genetic engineering.” Clearly ethics is outside the realm of science, but genetic engineering is most definitely within the realm of science.
Hanlon’s razor is a razor based on the assumption that people are ignorant far more often than they are malicious. In that respect it is reasonable to assume ignorance over malice. Frankly, I’m not sure which one of those really gives me greater subjective satisfaction.
Hitchen’s razor is a great example of protocol. It essentially places the burden of proof on the person making the claim. It is usually remembered as “that which can be asserted without evidence can be dismissed without evidence.” If the person making the claim cannot show evidence to support it, then there is no need to show evidence in order to deny the validity of the claim.
This is true regardless of the claim being made. It is not limited to those who make assertions of existence. If one asserts that something does not exist, it is still that person’s burden to provide evidence. This is also true even if the claim is made with less than 100% certainty.
People often confuse a rejection of a claim with the assertion of the negative claim. While we can reject an unfounded statement, we cannot say that the statement is wrong. Just that the person has not provided evidence to show that it is true. Saying a statement is wrong is a new claim and it would have to be substantiated.
Why is Hitchen’s Razor useful? It helps to prevent meaningless discussions. If assertions could simply be made without evidence, one could always come up with a counter argument for an argument being made. This counter argument could then be countered with another baseless claim. This also prevents endless loops of asserting the negation: “there is… there isn’t… there is… there isn’t…”
Lack of Evidence
Related to Hitchens razor is the confusion of how to use lack of evidence. For a given claim, if there is no evidence that it is not true, can we use that as evidence that it is true? How could we? What logical implication is there between a claim and lack of evidence against it? None, in general. There are cases, however, where lack of evidence is evidence to the contrary. This occurs when you can show that there should be evidence of a specific type, if the claim were true.
In what cases does lack of evidence constitute evidence to the contrary? We should start with an example. Suppose our friend, Jim, claims to have an elephant in his back yard. We know a fair amount about elephants. For instance, we know that they make loud noises and that they are very large and very heavy. So if we assume that Jim does indeed have an elephant in his back yard, we should be able to see it and hear it. If the ground is wet, we should be able to see foot prints.
Showing how to justify a claim of nonexistence will be addressed in more detail in Chapter II under probability theory and statistics. For this section, it is more important to realize that absence of evidence is not, in and of itself, evidence of absence, and it is indeed possible to prove a “negative” claim, or rather a claim of nonexistence. Indeed, while it might be linguistically obtuse, all claims of existence can be rewritten as claims of nonexistence and vise versa.
In philosophical discussions, there are no correct answers. Eventually, every argument boils down to first principals. These principals are unverifiable. However there are incorrect answers. The only way an answer is wrong is if it contains a logical fallacy. There is no winning or losing in a philosophical discussion.
Discussions in philosophy are not about proving your point right. After all, as mentioned previously, there are no correct answers. Rather, philosophical discussions are about coming to a better understanding of the nature of existence. Avoid putting the other person on the defensive. This is probably one of the worst case scenarios. What’s wrong with thinking of there being a winner and loser within an discussion? First, what does the winner receive? The winner may receive bragging rights—big deal; yet the loser gains a new view point and added knowledge. Therefore, quite often, the so called loser receives more than the so called winner. Once the other person is on the defensive, it’s no longer about the topic of discussion. Instead it becomes all about ego.
Avoid directly pointing out logical fallacies. This will often put people on the defensive, and on top of that, you then will need to defend your reason for calling an argument a fallacy. An alternative is simply to continue with more supporting arguments. With any luck, you can smooth over the fallacy. Being honest in a discussion is also very important. While this isn’t a trait found in every style of philosophical discussion, I find it’s helpful. Perhaps the only exception is the Socratic style which often bolsters the other speaker’s ego in order for them to let down their guard. However I can’t say I agree with this method since it seems to imply a desire to “win”. While there is no such thing as winning, an argument can fail. If we think of an argument as an exchange of ideas, then the way in which a failure can occur is when there is no longer an exchange. Once again, this often occurs when there is a desire to win or due to a misuse of logical reasoning or use of invalid information.
This topic will be useful in later discussions on science so I am including it in this chapter. The topic of reality is a complex one. What is reality? Is there an objective reality or is all reality subjective? Even if it is objective, can we ever know that we are truly seeing objective reality?
There are multiple philosophical debates along the lines of questioning reality as we think it to be. These include the “Brain in a Vat” and “Last Thursdayism” arguments. In general, we cannot determine whether our experiences are real. If we experience something which is contradictory to our assumption that the world around us is as we see it, then we can reject our assumption that our experiences are real. But we are forced to assume that reality is as we see it.
1. Chapter I Quiz
2. Chapter II
3. Prior Analytics, by Aristotle (Free Digital Copy from the University of Adelaide)
4. Nonsense: Red Herrings, Straw Men and Sacred Cows: How We Abuse Logic in Our Everyday Language
5. The Cambridge Companion to Aristotle (Cambridge Companions to Philosophy) [Paperback]