The human organism is a marvelous system, with multiple defense mechanisms that operate to keep the organism functioning. These mechanisms operate at an unconscious level, so that the person is not aware of them. When a disease-causing bacteria or virus enters the system, the body produces white blood cells and activates the immune antibodies to destroy the invader.

The mind, too, has many defense mechanisms. Some of these function to maintain a state of comfort. Unfortunately, these well-intended maneuvers may sometimes backfire. For example, it has happened that a woman who discovered a lump in the breast may be so anxious about the possibility that it may be cancer, that in order to relieve the anxiety, the mind produces the defense of denial, so that she becomes oblivious of the lump. Obviously, the elimination of anxiety by means of denial can be a serious mistake, because if the lump is cancerous and is not attended to, it may cost the woman’s life.

One of the common mental defense mechanisms is rationalization, whereby the mind conjures up logical and reasonable ideas to cover up the truth. Because rationalization camouflages the truth, it is self-deceptive. It should be apparent that self-deception is counterproductive.

There are two major faculties of the mind: the affective and the intellectual. The affective is comprised primarily of physiologic desires, and the person implements the intellect in order to gratify these desires. Animals, too, have intellect. Anyone who has seen the lion or cheetah stalk its prey has seen how keenly the animal calculates its attack. When man uses his intellect primarily to gratify his cravings, he is merely a highly sophisticated animal.

The human intellect can be ingenious in gratifying one’s cravings, and we must be on the alert for these self-deceptive mechanisms.

In Deuteronomy (7: 4-6 24-26), Moses warns the Israelites against being lured by the idol worship of the Canaanites. In Deuteronomy (12:29-30), Moses repeats this warning, saying, “After you have conquered Canaan and displaced them, be cautious lest you adopt their idolatrous practices.” This latter warning appears superfluous. Once they have conquered Canaan, it should be evident that their idol worship was a fallacy, because their gods did not protect them. Why would the Israelites be tempted to adopt a religion which is patently false?

Netziv explains that the Israelites might think, “True, the Canaanite gods did not protect the people. However, inasmuch as the Canaanites did survive in the country for centuries, perhaps it was these gods of theirs who sustained them.” Therefore, Moses had to caution them against such fallacious reasoning.

But how foolish can people be? This rationalization is so absurd that no clear-thinking person could succumb to it.

True, a clear-thinking person could not possibly be duped. But we may not always think clearly.

The Talmud says that the Israelites never believed that there was any substance to the idols, but they were attracted to idolatry because it permitted them relationships which the Torah forbade. In other words, their desire for the forbidden relationships so influenced their thinking that they sought sanction for their behavior.

Moses knew how susceptible the Israelites were to justify their cravings, and that the rationalization described by Netziv, as absurd as it is, was a distinct possibility.

The Torah is alerting us to our vulnerability to self-deception. We may be “bribed” by our desires, and as the Torah says, (Deuteronomy 16:19), a bribe can “blind the wise and distort the thinking of even the righteous.”

How can we protect ourselves from self-deceiving rationalizations? Rabbi Yisrael of Rhizin said, “The way a tightrope walker keeps his balance is that when he feels himself pulled to one side, he leans a bit toward the other side. When you feel yourself drawn to do something, pause and think why you should not do it.”

Another safety measure is to seek the advice of a wise person, whose thinking is not affected by our biases.

We pride ourselves on being intelligent creatures. We must be cautious that we do not misuse our intellect.