Spinoza, Spock, and the Jewish “Inclinations”

This article was originally published in Jewish Sacred Aging on November 6, 2024 and is re-posted here with the permission of the author, Rabbi Edmond Weiss, Ph.D. Dr. Weiss is a writer, lecturer and retired professor, who received his rabbinical ordination in 2018 at the age of 75. He develops courses, workshops, and seminars for adult Jewish education. To read more of Dr Weiss’s work, click here!

A foundational idea in the Jewish conception of ethics is that our choices and actions involve a clash between two conflicting forces or “inclinations”: the yezer hatov and the yetzer harah.

The two terms are nearly always translated, misleadingly, as the good impulse and the evil impulse. I say “misleadingly” because the inclinations themselves are neither good nor evil, but rather their consequences tend to either be desirable or undesirable. The so-called evil inclination is more correctly understood as the dictate of the appetites, the pursuit of immediate gratification. The so-called good inclination is more correctly understood as the application of controls that will provide for longer-range benefits and gratification.

Jewish sages, notably Nathan in his famous commentary on Pirkei Avoth, explains that we are born with this yetzer harah, that it is in our biological nature, but that it takes 13 years before we acquire the yetzer hatov, the commitment to observe the commandments rather than our immediate impulses. The sages also explain that is difficult for the yetzer hatov, to compete, because the yetzer harah, has a 13-year head start. Rashi adds that at 13, the emerging sexual impulse is the most difficult inclination to contain.

From this perspective, the Ten Commandments can be seen as a list of warnings against acting on impulse: lying, stealing, coveting, killing, fornicating and anything else that seems attractive at the moment, but will make civilized community life impossible. But, the mere fact that they are commandments, tells us that we don’t really want to follow them when our short-term appetites and emotions are stimulated.

While our ancestors were assembling the Hebrew Bible, Plato was making a similar point in his Phaedrusdialogue. In it, he pictures the human mind as a chariot being pulled by two horses, one unruly and headstrong (emotion), the other disciplined and cooperative (reason). The eternal ethical struggle is to overpower the emotional horse with the rational horse—a struggle that too often is won by the emotional horse.

This struggle exists not only in the mind but also in the brain. We are born with a fully functioning neural component called the nucleus accumbens, a system for (among other things) rewarding our brains with dopamine—pleasure. Without this component, our hunger would not be gratified by eating. In later life, the nucleus accumbens plays a role in addiction and other mental disorders. In short, much of our behavior—including behaviors necessary for our survival—emanates from this part of our brain. It is, effect, the yetzer harah.

In contrast, the prefrontal cortex component of the brain, which continues to develop for about 20 years after birth (not just 13) is the part that plans, defers gratification, evaluates the consequences of our emotions. It clearly is the neurological analogue for the yetzer hatov, putting long-term gratification ahead of immediate satisfaction.

There is no disagreement, then, among philosophers, religious leaders, and neuroscientists that the tov-rational-cortex inclination should prevail in ethical conflicts. The big, important, unanswered question is: Can reason reliably defeat emotion? Or is emotion too powerful to resist?

Although Aristotle believed that emotion always overpowers reason, Spinoza (the 17^th Century Jewish philosopher, excommunicated from his synagogue for his dangerous ideas) argued that the only thing more powerful than an emotion is another emotion. And, therefore, he proposed a new kind of emotion: the intellectual love of God.

In Spinoza’s scheme, there are two kinds of emotions (or passions). Some (the ones he calls “inadequate”) are attached to external objects, like jealousy (of another person) or addiction (to wine or food). In contrast, there are “adequate” passions, which emanate from the person himself and are not influenced by outside objects or events. As it happens, there is only one example of this kind of emotion:the joy associated with the highest form of knowledge, which Spinoza also calls the intellectual love of God.

(By God, Spinoza means “the fixed and unchangeable order of nature or the chain of natural events: for I have said before and shown elsewhere that the universal laws of nature, according to which all things exist and are determined, are only another name for the eternal decrees of God, which always involve eternal truth and necessity.”)

Again, though, we must ask whether any ordinary human being can attain the intellectual plane that Spinoza describes (and appears to have achieved in his own short and troubled life).

The only person I can think of is not an ordinary person at all, but rather the character Spock in the Star Trek TV/movie franchise. Spock is the offspring of a Vulcan father and a human mother. Vulcans are famous for their ability to suppress their emotions (or their lack of emotions, it’s not clear) and always act logically, and Spock clearly favors his father. Although he shows an occasional flicker of emotion (notably vanity and smugness), he always makes the rational, logical choice.  His affect is flat and unchanging and the harshest opprobrium in his vocabulary is “illogical.”

Indeed, in the second movie of the Stark Trek series, he performs the ultimate act of rationality when he elects to sacrifice his own life to save the hundreds of lives aboard his vessel. With Bentham-like calculation he argues that the needs of the many outweigh the needs of the few or the one.

Probably, in the evolution of the Vulcan race, the power of the nucleus accumbens diminished. And, since everyone agrees that such a change would be a good thing, is there an evolutionary incentive for such a change to occur in the human race as well? Would we want to be like Spinoza or Spock?

Alternatively, when AI reaches a point where it can do everything better than our prefrontal cortexes, will humans elect to delegate management of our lives to the wise machines, freeing us to live happy, dopamine-drugged lives like the primates we really are? (And isn’t that what the mystics and spirituality-vendors are always promoting?)

Or is the eternal struggle between the two inclinations what really makes us human? I am reminded of Kirk’s eulogy for the self-sacrificed Spock:

“He did not feel this sacrifice a vain or empty one, and we will not debate his profound wisdom at these proceedings. Of my friend, I can only say this: Of all the souls I have encountered in my travels, his was the most human.”