A formal logic class or textbook should teach us ways to know when an argument has a valid argument form, and that can take a significant amount of time to learn. I encourage everyone to learn formal logic one way or another because it is of central significance to rational argumentation, and it is not something we spontaneously understand instinctively or through personal experience. Perhaps the first philosopher to understand formal logic and the importance of validity was Aristotle, and philosophers would have liked to understand it sooner. It was a great achievement because it can be so difficult to figure out on our own. Even so, we can learn a lot about valid argument form very quickly. I will explain why we need to make sure our deductive arguments are valid, give examples of valid argument forms, and explain how we can improve our arguments. (more…)
May 13, 2013
March 6, 2013
Recommended reading: What is Logic?
Why is logic education important? The main question here is what the real point of logic education is. The real point of logic is not to teach people how to be logic professors, or to increase test scores, or to impress potential employers. Philosophers and mathematicians were very interested in understanding logic long before it was taught in universities precisely because of how important it is. Why is logic so important? The answer is that logic helps us better understand good arguments—it helps us differentiate between good and bad reasons to believe something. We should want to have well-justified beliefs. We want to know what we should believe. Understanding good argumentation helps us understand when we should believe something, and understanding logic helps us understand good argumentation. (more…)
February 26, 2013
Do extraordinary claims require extraordinary evidence? Is there a burden of proof against extraordinary claims? Should we literally assume that something extraordinary doesn’t exist until it is proven to exist?
Many people say that those who claim that bigfoot, ghosts, and gods exist are making “extraordinary claims” and we should reject the existence of these things because we don’t have enough evidence for them.
What’s “extraordinary” mean? It refers to claims that conflict with what we think we know about the world. Many claims are extraordinary because they are extreme (likely false) or potentially impossible. (more…)
May 21, 2012
May 15, 2012
The term “default position” refers to a belief (or lack of belief) that is preferable prior to debate or before any evidence is considered. Many people claim that some belief (or lack thereof) are default positions, so everyone who disagrees with those positions has the burden of proof. What exactly is a default position, and do default positions exist? (more…)
May 6, 2012
One of the most confusing topics regarding argumentation and rationality is what we call the “burden of proof.” What is it? Who has a burden of proof? I will argue that there are two kinds of burden of proof—(1) a principle of debate and (2) a principle of rationality. These two principles are similar but there are important differences. As a principle of debate, the burden of proof determines who needs to prove their assertions. As a principle of rationality, it determines what beliefs are irrational without further evidence in their favor. (more…)
February 15, 2012
What are valid arguments, why are they important, and why is validity often insufficient to have good arguments? I answer these questions and illustrate various points using argument maps.
February 2, 2012
This is part 2. You should read part 1 first.
I have argued that beliefs are innocent until proven guilty and various objections have been raised to this position and my arguments. I will provide some clarification and respond to various objections here. (more…)
January 18, 2012
Many people equate “justified” with “justification”—they think beliefs are justified if and only if we give a good justification for them. A sign of this attitude is found in statements such as, “We should only believe something if we can observe it’s true.” I will explain that not all our beliefs require justifications to be justified because (a) we have justified beliefs that we can’t give justifications for, (b) such an assumption is self-defeating, and (c) such an assumption would lead to an infinite regress or vicious circularity. (more…)
September 29, 2011
Do you think everyone has to agree with you about something? Do they have to agree that God exists, Christianity is true, atheism is true, Islam is evil, libertarianism is true, socialism is true, Obama is the antichrist, or Harry Potter is satanist propaganda? Many people seem so confident that they’re right and they know that you need to agree with them. The other person might think that you’re an idiot for not agreeing. This attitude of certainty and confidence often leads to intolerance and insults. Of course, few people are perfect and almost everyone suffers from over-confidence and immodesty at one point or another. (more…)
September 19, 2011
We should generally prefer beliefs and theories that are well justified and don’t require ambitious metaphysical or religious assumptions. “Metaphysical” beliefs are beliefs about reality, and “ambitious” beliefs are difficult to justify in a satisfying way that would lead to anything resembling certainty. We attain absolute certainty when we have a belief that couldn’t possibly be wrong. (more…)
July 19, 2011
June 7, 2011
We can learn how to think more like a philosopher by engaging in philosophical debate, reading philosophy, thinking about the nature of philosophical argumentation, and examining the thought process of philosophers. A philosophy professor can be very helpful as a guide to help people engage in philosophical argumentation by helping them verbalize their arguments and avoid fallacious reasoning. Since I am writing about philosophical argumentation, I am not able to help guide your philosophical thoughts as you engage in philosophical debate. However, I can help you peer into the thoughts of someone who engages in philosophical thought. In particular, I will discuss the thinking involved with constructing a philosophical objection. (more…)
June 2, 2011
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: (more…)
June 1, 2011
May 31, 2011
An argument uses premises to reach a conclusion, but we can’t just accept that every valid argument proves the conclusion to be true. If an argument has a valid form, we need to know that the premises are true before we can know the conclusion is true. We rarely know for certain that the premises of an argument are true. Instead, we do our best at justifying the premises. One way to do this is to provide evidence—reasons we should believe something to be likely true or accurate. Many people equate “evidence” with “observation,” but there could be other reasons to accept beliefs as well. I will discuss three types of evidence: (more…)
May 21, 2011
May 20, 2011
April 20, 2011
Our arguments depend on assumptions. We prefer these assumptions to be intuitive and coherent with our other “knowledge” rather than counterintuitive and incompatible with our other “knowledge.” We might not be able to fully explain how we know “1+1=2” but we find it to be an intuitive belief, and we think it’s absurd (and perhaps incoherent) to deny that it’s true. Intuitive arguments are not only very common in philosophy, but it’s possible that all our justifications are grounded in intuition in one way or another. (more…)
March 31, 2011
Philosophers often discuss what beliefs are intuitive or counterintuitive to support their conclusions. I will argue that we should prefer theories and beliefs that are intuitive or sensitive to our intuitions rather than ones that aren’t.1 The fact that a theory or belief is intuitive isn’t conclusive proof and a theory or belief being counterintuitive isn’t a conclusive disproof, but it is one important element when evaluating the plausibility of a theory or belief. Intuitive beliefs range from things we know with high degrees of confidence—such as “1+1=2”—to beliefs that are merely plausible enough to take seriously as “possibly true.” When a theory isn’t intuitive, then we call it counterintuitive, absurd, or revisionistic. Revisionism exists in degrees from not at all to totally counterintuitive. I will argue that we should prefer that our theories are intuitive rather than revisionistic for at least the following three reasons: (more…)