A+B=C. I reject C. Therefore, B is false.

If I stated the preceding syllogism in an argument in those plain terms, you’d immediately see and point out at least one obvious fallacy (there are actually two). You would never think of making such an absurd statement yourself. Yet I have encountered it on several occasions in discussions with relatively intelligent people who are really quite serious.

The two fallacies (both probably having technical names unknown to my rhetorical ignorance) are these:

1. I reject C, therefore B is False. This is the most obvious fallacy, ascribing authority to yourself. You reject C. So what? Irrelevant. Now, if you can explain why C must be rejected, maybe you’ll be on to something.

2. A+B=C. Are you sure? Or is this possibly a non sequitur? Does it necessarily follow that A, combined with B, leads to C?

I’ll give you a couple of examples.

In a recent conversation about genealogies, I disclosed that my maternal grandmother’s family has been in this country since before the American Revolution. I stated that a pair of brothers from that family had, in fact, been given land in Canada by George III for “acts of loyalty to the Crown.” Apparently, this is something that should embarrass me (it does not).

Well, the conversation turned to the legitimacy of the Colonial rebellion. I have no settled opinion on that, but I do not believe the rightness of the insurrection is at all obvious. This provoked the A+B=C argument.

“If the colonists hadn’t rebelled,” it was said, “we’d all still be speaking English!” No, not really. Said he, “We’d still be English subjects.” A=subjection to England. B=no revolution. C=continued subjection. A+B=C. Subjection to England is unacceptable, therefore, the Revolution must have been right and necessary.

We apply the two questions above. First, was subjection to the King really — from a biblical perspective — intolerable? Maybe, but you will have to establish that based on facts, not your own feelings. Second, does it necessarily follow that the colonies could not have gained their independence by other means? The answer to that is an obvious no. Those arguments are invalid. That doesn’t mean that the American Revolution was an illegitimate rebellion; it only disposes of that argument.

For another example, many people respond to the doctrine of Perseverance of the Saints, or “eternal security,” with something like this: “If you can never lose your salvation, you could get saved and then do whatever you want!” The implication is that without the threat of damnation hanging over our heads, we would most likely live licentiously. A=salvation. B=no threat of hell. C=an unsanctified life. A+B=C. An unholy life is unacceptable, therefore, the threat of damnation must continually hang over us all.

Fallacy checking, we ask, is that really unacceptable? At first, it would seem so. The idea of a redeemed person living in sin is certainly not to be found in Scripture. But what of a regenerate person doing “whatever he wants”? If we throw out the so-called “Free Grace” view — which we most certainly will — and see how the Bible describes genuine believers, we see that the believer is a new creature, filled with the Holy Spirit, whose desire is to be pleasing God; so a regenerate person doing whatever he wants will be living in obedience to God’s Word. Therefore, while in this case A+B does in fact =C, C should not be rejected. The doctrine of Perseverance does not encourage licentiousness. In fact, it guarantees increasing holiness.

Think about it: do you ever argue for or against a truth statement based on its possible consequences rather than its intrinsic truth or falsehood? Don’t do that.