Stupidity or foolishness is a product of sin (Proverbs 24:9). In fact, the Bible associates foolishness with transgression ((Psalms 107:17; Proverbs 13:15; 17:18, 19 ), and with sins such as:

• atheism – Psalm 13:1
• blasphemy – Psalm 74:18
• contention – Proverbs 18:6
• hypocrisy – Luke 11:39–40
• materialism – Luke 12:16–21
• mischievousness – Proverbs 10:23
• slander – Proverbs 10:18
• wastefulness – Proverbs 21:20.

So, yes, the Bible says that sin makes you foolish. It explicitly says, “Some became fools through their rebellious ways and suffered affliction because of their iniquities” (Psalm 107:17). Even the common sin of “Extortion turns a wise person into a fool, and a bribe corrupts the heart.” (Ecclesiastes 7:7) Further, in Psalm 74:18 we see that enemies of God (sinners who mock and revile His name) are called “foolish people.” See also Psalm 74:22–23.

When Aaron and Miriam incurred God’s wrath for murmuring against Moses, Aaron pleaded with Moses, “Please, my lord, I ask you not to hold against us the sin we have so foolishly committed.” (Numbers 12:11) Sin obviously makes one to be foolish. Moses describes the Israelites who sinned during their wilderness journey thus:

They are corrupt and not His children; to their shame they are a warped and crooked generation. Is this the way you repay the LORD, you foolish and unwise people? Is He not your Father, your Creator, who made you and formed you? (Deuteronomy 32:5–6)

The sinful behavior of King Saul made him to do foolish things. When he partially obeyed God’s command regarding the destruction of the Amalekites, Samuel said pointedly to him, “You have done a foolish thing” (1 Samuel 13:13). Moreover, Saul himself admitted after chasing the innocent David down to the Desert of Ziph with his three thousand select Israelite troops, “I have sinned. Come back, David my son. Because you considered my life precious today, I will not try to harm you again. Surely I have acted like a fool and have been terribly wrong.” (1 Samuel 26:21, emphasis added)

Many examples abound in Scripture which prove clearly that sin can make you stupid. Remember David’s first son Amnon. When he wanted to rape his half sister Tamar, she cried out to restrain him but he didn’t listen: “What about me? Where could I get rid of my disgrace? And what about you? You would be like one of the wicked fools in Israel. Please speak to the king; he will not keep me from being married to you.” (2 Samuel 13:13)

Even their father David confessed after he had arrogantly counted the fighting men in Israel, “I have sinned greatly in what I have done. Now, LORD, I beg you, take away the guilt of your servant. I have done a very foolish thing.” (2 Samuel 24:10, emphasis added). Ever since David committed adultery with Bathsheba and killed her husband (2 Samuel 11–12), sin started to make him and his children to do foolish things.

-by Pat Flynn

“The traditional thought is that sin not only makes us weak, but stupid. Sin blunts conscience progressively over time—that is, diminishes our grasp of moral reality, impairing our ability to reason to proper moral conclusions. Consequently, sin can (and often does) lead to greater sin, along with the failure to realize not just that we are sinning, but also how awful our sinning has become.

So many of us sinners (myself included) have consciously lived through this experience. We do, at first, feel the pangs of conscience when rejecting the right course of action. We fail to choose what we know is the right thing to do; we make, as Boethius called it, a moral miscalculation, because we engage in voluntary ignorance. Should I drive even though I’ve been drinking? gives way to the need to get home quickly.

At first, we feel bad about it. We know, intuitively, that we are violating the objective moral rule. But if we keep at it, our conscience dulls. The evil becomes more comfortable, opening us up to exploring and enacting further, and often far graver, sins. We become gutsy.

This is true not just of individuals, but of society. Just as an individual, through sinning, becomes prone to further sinning and increasingly incapable of acknowledging that he is sinning—in many cases even defending his evil action as good—society can suffer the same effect. Society’s moral conscience dulls as well, leading to increasingly horrific evils and the collective rationalization of such evils as good. Do we need examples from history on this? Slavery, abortion, genocide . . . the list continues.

Here’s a more recent one. People are surprised not just that children are being hypersexualized (groomed—a perfectly appropriate word), but also that society itself doesn’t outright reject this practice. In fact, society often supports it or is indifferent to it. But why should this surprise us? Our culture, after all, has been so morally impaired for so long, especially concerning sexual ethics—so why should we expect everyone to suddenly awaken to the abject horrors foisted upon children, from putting them onto stripper poles to mutilating their genitals and injecting them with puberty-blocking hormones? I suggest that, like the individual sinner, our collective moral conscience is gravely impaired, so it should be expected that such moral atrocities occur, unencumbered by any societal roadblocks.

Thus, when one sees some abject moral evil, he finds it accompanied by obnoxious comments like, “Shame some people just aren’t capable of having an open mind.”

As if having an open mind were always inherently a good thing! (“Don’t have such an open mind your brains fall out!” -G.K. Chesterton) On the contrary, having a closed mind is often undoubtedly the best approach—including when it comes to having sexual relations with young girls as a 47-year-old man, or drinking Clorox, or mass murder, or whatever other insane notion there is to propose. The slogan of keeping an open mind in this context is just the result of somebody whose conscience is thoroughly corrupted, who cannot see the evil for what it so obviously is. You might as well say it’s a shame that someone isn’t so open-minded as to think two plus two might actually equal five. What should really be said is that it’s shame some people are not more closed-minded.

A sinful excess of open-mindedness is the predictable consequence of a life lived in sin, especially sexual sin, individually and collectively. And it’s hard to fight this problem with reason, as there is little to no reasoning to be employed against people defending abject depravity. We must have some common ground for an argument to be fruitful, but if someone’s moral faculty is so impaired that he no longer shares the same ethical framework as you, how can you make any moral progress?

As Ed Feser writes, “repeatedly taking sexual pleasure in activity that is directly contrary to nature’s ends dulls the intellect’s perception of nature, to the point that the very idea that some things are contrary to the natural order loses its hold upon the mind. The intellect thereby loses its grip on moral reality.”

Here Dr. Feser is drawing from the deposit of St. Thomas’s wisdom, where Thomas discusses the Daughters of Lust, or how someone, through repeated sexual sin especially, can suffer “blindness of mind, thoughtlessness, rashness, self-love, hatred of God.” Aquinas tells us that the more unrestrainedly bent our lower powers (or concupiscible appetites) are upon their object, the more easily distorted our higher powers—namely, reason and will—become. In other words, an unhealthy obsession with sex makes it hard to think straight. I mean, duh. Reason has almost completely checked out, except to make excuses for vile behavior.

What is the way out of this mess? God’s grace, surely. But also setting better examples and living the Christian ethic fully—especially the Christian sexual ethic—to attract those non-religious folks who are still, thankfully, repulsed by the increasing deceptive darkness that just is the logical extension of the Sexual Revolution—from the constant promotion of pornography and masturbatory practices to contraception and seeing others as mere instruments of self-pleasure to redefining marriage to feign the illusion that two people of the same sex can actually be married, and so on.

There are still many people who are seriously repulsed by what is being foisted upon children. Where will they be able to find shelter and help? Let it be the Church. By wanting to escape the darkness and make sense of this growing perversity and its origins, they may be brought fully to the light of Christ.”

Love & truth,
Matthew