Celtic Riverside – The Online Journal of James Keenan

That Logic


What follows is a futile undertaking – discussing logic. The tragedy of logic is that people who do not understand logic are not particularly receptive to its discussion. In many ways it is the antithesis of preaching to the choir.

Still, I feel obliged to make the effort because the discourse in this world, especially in digital forums, leaves much to be desired. First, some people seem to lose sight of the purpose of their communication. We communicate to inform, to persuade, and to entertain. They may overlap to some degree, such as John Oliver’s “Last Week Tonight” program, but one purpose must take the lead.

Second, and within the context of those purposes, are the modes of persuasion: ethos, logos, and pathos. When attempting to persuade or entertain, we may rely on any of these. When attempting to inform, we rely heavily on logos – logic. This post is going to focus on that specific element.

Logic – An Introduction

Imagine a sidewalk baking in the summer sun – no trees, no cover, and no shade of any kind. A few hours later that same sidewalk sits drenched under a cloudy sky. Logical conclusion: it rained. Not necessarily, and that is the focus of the discussion today.

One might say, “If it is raining, then the sidewalk is wet.” This is not a conclusion, but the first premise of an argument. In a proper situation, one would continue, “It is raining” as a second premise and then conclude, “Therefore, the sidewalk is wet”.

Simple, right?

However, one might also say, “The sidewalk is wet, therefore it rained”. This has the superficial appearance of being right and, this is a key tenet of this conversation, it may very well be, but the premises do not support that conclusion (a fallacy known as affirming the consequent). Perhaps a sprinkler system is responsible for the wet conditions, or perhaps someone spilled water. Another version of this might be the argument, “If it is raining, then the sidewalk is wet. It is not raining. Therefore, the sidewalk is not wet” (denying the antecedent). As in the first case, this omits alternative explanations. It does not condemn the conclusion drawn, as that is certainly one of the possible scenarios, but logic dictates that this is poor reasoning.

Thus, we find that a person might walk down the street, come to that section of the wet sidewalk, and conclude that it rained. If no other person is around or if any other persons who are around agree that rain caused the situation, no conflict arises. The conflict occurs when someone else suggests that the sprinkler system in the adjacent lawn is the culprit and an argument ensues.

Let us next raise the stakes slightly and say that the sidewalk is not wet but flooded to a disruptive degree, and the matter at hand is how to prevent the flooding. Now it matters considerably more why the sidewalk is wet because different root causes of the wetness will have or may have different solutions. If the sidewalk accumulates rainwater, then repair to the sidewalk itself is the answer. If the culprit is the leaky sprinkler system, it may be more effective to repair that instead.

If one comes along with the argument, “If it is raining, then the sidewalk will flood. The sidewalk flooded. Therefore, it must have been the rain” (denying the affirming the consequent) then the responsible party might undertake the wrong corrective action.

Logic is the study of methods for evaluating the reasoning of an argument, and an argument is a series of premises upon which one draws a conclusion. That definition is critical to understanding this discussion because, as one will see, the criticism that follows has nothing to do with the conclusions or beliefs but rather how one arrived at that point. When humans interact, we do so with a considerable degree of belief, internal logic, and cognitive bias that results in the fallacious thinking displayed in this sidewalk example, and failure to recognise that – and the related presence of anti-intellectualism and scientific illiteracy – results in countless problems.

Practical Application

 Many readers either already understood logic to that degree or, at minimum, were able to follow that definition. That is what makes this topic so frustrating. One might hear something to this effect: “What if we applied that logic…?” There is no “that logic”; there is only logic. When we say we are applying “that logic” to a new subject what are saying is, “Let us apply the same pattern of reasoning as we did with that subject”, which is to ignore the logic. We are not evaluating the reasoning of the argument; we are applying it blindly in a new situation.

Example: a meme suggested that Democrats said, “If Trump wants a wall, he can start a GoFundMe page, and his supporters can pay for it”, to which some supporters retorted, “Apply this logic to abortions and universal healthcare”. Put aside the absurdity of the arguments themselves and focus on the language – “apply this logic”. What the retorting party means is something more akin to, “If the attitude here is that citizens should directly fund things that a large portion of Americans do not want, then why can we not apply that reasoning to abortion and universal healthcare?”

That latter question is fine. If we as a people cannot accomplish something through legislation at the desired social level (municipal, state, federal) are we then free to pursue it through private means? Whatever the answer, logic is then the process of evaluating the reasoning we used to reach that conclusion. One cannot then transfer that reasoning to the other situation without then re-evaluating the reasoning.

For example, let us assume that we conclude that the government will not provide or subsidise abortions or universal healthcare but, as they provide benefit to persons without harming others they may be available if private citizens fund it (again, assume – I understand the argument that abortions do not “harm no one” – we are not here to debate abortion though). If we then conclude that building the wall brings harm to some, despite the benefit it provides others, we might raise a deontological argument that the wall cannot be built with any funding. The reasoning does not translate from one situation to the other as indicated by the logic.

Here is another example from the gun control debate. One party raised the argument that the United States has tens of thousands of gun control laws on record already, so the push for additional gun control legislation implicitly but clearly posits that legislation does not work. However, one could argue that the United States has over 300 million privately owned firearms, therefore the argument that a “good guy with a gun stops a bad guy with a gun” also fails. If the latter sound specious, that is because it is. However, it is no more specious than the first one. The existing legislation may be outdated, impractical to enforce, or simply lack efficacy. That no legislation to this point sufficiently addresses the issue of gun violence does not mean that legislation is not the solution. One would have to take another step back and establish the reasoning behind the failure of the existing legislation, then use that as the premise for an argument against further legislation.

A Logic Conclusion

In matters of personal belief or discussions among a small group, logic may be of little consequence because the internal logic of that person or group may allow it. Internal logic covers things such as the suspension of belief in movies that Thor can wield Mjolnir as he does or that one can survive an atomic explosion and violent collision by sheltering inside a lead-lined refrigerator. Internal logic says, “Within the context of this discussion, this line of reasoning is acceptable”. Rules still exist, but specific to that situation.

When dealing with most issues though, we rely on the shared objectivity of formal logic. Two and two must always equal four. If I want to debate with a friend whether a Jedi could use the Force to move Mjolnir, we would have to reach some agreement about the rules of that situation, as we cannot rely on the distinct logics of the Star Wars and Marvel universes. Being raised Roman Catholic, I cannot rely on my spiritual education to convince a Buddhist or an atheist about something – there is an internal logic to religion based on faith. Promoting a Roman Catholic value among non-Roman Catholics will mean relying on objective premises on which we can all depend.

That takes us back to the matter of scientific literacy – how does one know if something satisfies formal logic as opposed to some sort of internal logic? The truth is that we never really know in the scientific sense, but we can determine things to a high degree of probability through reproducibility and reliability. We need well-defined premises with true values that, likewise, have a reliably determinant value, and then we need a process of causality through to the conclusion that is reproducible.

As a Roman Catholic there was a great deal of “because God said it should be so” and we know that because of the Bible. However, one must put aside pride and acknowledge that to a non-Roman Catholic one is saying, “We must do this because an entity that has no tangible proof of existence reportedly said so, as recorded by the hand of man in this book”. Millions of people have faith in that, but it does not qualify as sufficient evidence for billions more. To the non-Roman Catholic then, we must first establish that the Bible represents God’s will and, as prerequisite to that, that God exists. Alternately, we can find arguments to support the conclusion based in scientific objectivity rather than the religious belief and use those to persuade the majority of society. Religion and science are not incompatible, and religious institutions have a history of engaging in scientific research.

All of this goes without addressing the complexities of cognitive bias and logical fallacies, but let us save these for another time.

2 Responses to “That Logic”

    • James Keenan

      Thank you for the kind words, Dan! I enjoyed your piece as well, and wanted to tackle specific fallacies. Fallacies are powerful persuasive tools, but they are often cheap tools used to promote the losing side of a debate to overcome a lack of logic.

      These messages need to reach more people and teach them to identify fallacies masquerading as logic in our everyday conversations because the discourse has only become more vitriolic.



Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Basic HTML is allowed. Your email address will not be published.

Subscribe to this comment feed via RSS

%d bloggers like this: