Yes, precisely. One cannot coherently use logic to justify logic. To do so would be to implicitly assume the reliability of the logic used to do the justification. This assumption is itself a logical fallacy (assuming the consequent – assuming what one intends to demonstrate in order to do the demonstration). Therefore the force or substance of any sensible “argument” that is made to “justify” logic will not itself be logical (although if it is put into words it may rely on logic to some extent, inasmuch as an argument is put forth in language which depends implicitly on logical principles).
So if such a justification of logic is not essentially from logic itself, what might we expect it to consist of?
Yes, the justification of logic should consist of an explanation of why we trust logic. The root of the word “justification” is from latin, meaning “to make lawful”. Lawful actions are the ones that we as a community trust, actions that we believe will not hurt us. Similarly, a justification of logic is an attempt to persuade us that logic is trustworthy. But if we are fearful and obsessed with certainty we will ask to be persuaded that our method of determining trustworthiness is itself trustworthy, and then this persuasion will itself be called into question, creating a vicious cycle of second-guessing. The only way to avoid the vicious cycle is to relax our obsession with certainty. To perform this mental relaxation, we can say something like this:
Yes, logic is uncertain. I accept the possibility that my use of logic may one day lead me astray, even if I use the logic perfectly, because logic might be wrong and lead to very bad things. In fact, I even accept that I might abuse logic because I’m an imperfect human being. Whatever imperfections in logic or my use of it, they might lead to me believing ridiculous shameful falsehoods, it might lead to my world crashing down on me. Yes, they very well could! Perhaps if I use logic I will lose all my friends, become ugly, grow hair on my palms, and be banished to an 80s karaoke bar for eternity. Yes, it could happen! But these possibilities are just possibilities. I’m under no obligation to fear them. I can choose for myself whether I will fear that logic is untrustworthy and might lead to falsehood and bad things. I can decide whether I will let fear overcome my logical instincts. And yes, I am okay with the fact that logic is not ‘certain’. It’s still trustworthy, because I myself have deemed it worthy of trust.
You see? Most people do not obsess about certainty. Think of the people that you admire. Do you think they worry about whether logic is trustworthy, or do they trust it and move on to more interesting things?
Yes, we can, because we are not forced to fear and obsess about logic being wrong. For all we know, it could be very bad and horrible to doubt logic. There is no compulsion either way, for as the Greek Skeptics noted, most every argument, every possibility, can be met with one that leads to an opposite conclusion. These Skeptics concluded that because no argument is ever conclusive and every argument can be met with an opposite argument, it’s best not to believe anything at all. But they didn’t understand the true force of their own reasoning! We can turn their argument against them, as they themselves admit. We can say (ever so skeptically) that the skeptics themselves might be wrong, and that just because arguments are not conclusive doesn’t mean we shouldn’t believe anything. You see, just because arguments are not completely certain doesn’t force us to avoid believing anything. That is a decision we have to make for ourselves.
If you ask what my conclusion is, I say be brave! You know you trust logic like a close friend, or like the bicycle you’ve ridden for years. Should you avoid your friend because you think it is possible he will betray you, or your bicycle because you think it is possible it will fall into pieces under you while you ride it? Of course not! Of course you are right and it is possible that these bad things will happen. Embrace that possibility, accept it and feel it in your heart. But then, realize that that doesn’t mean that your trust has to be shaken. You and you alone get to decide what you will love and what you will fear, what you will trust and what you will suspect.
