(Please excuse the reference to a terrible song from the early eighties.)
With Halloween just around the corner, I thought it would be appropriate to consider how our tradition addresses "the occult". Of course, practicing magic, conjuring up spirits and consulting astrologers are all strictly prohibited by the Torah:
There shall not be found among you one who passes his son through the fire; a diviner, an astrologer, one who reads omens or a sorcerer. One who charms animals, one who inquires of Ov or Yideoni, or one who consults the dead. For anyone who does these is an abomination of Hashem; and, because of these abominations, Hashem, your God, banishes the nations from before you.
Famously, Maimonides explains that these activities are forbidden because they are nonsensical:
And all of these things are matters of falsehood and lies, and they are the very means through which the idol worshipers fooled the nations of the world into following them. And it is not proper for the Jewish people, who are exceptionally wise, to follow after these vanities, nor to entertain the possibility that they have any benefit. As the Torah states, "there is no divination in Jacob, nor charming in Israel." And it is stated, "For these nations that you will inherit listen to the omen-readers and charmers; but you, not so has Hashem, your God, given you."
Anyone who believes in these things and things like them, and thinks in his heart that they are true and wise but that the Torah has prohibited them; he is one of the fools and those lacking knowledge, and is grouped among the women and children whose minds are imperfect. But those who possess wisdom and sound mind know by clear demonstration that all of these things that the Torah prohibits are not things of wisdom; rather, they are emptiness and vanity that fools stray after, and all of the paths of truth have been corrupted because of them. Because of this the Torah states, when it warns us about these vanities, "Perfect shall you be with Hashem, your God."
In the Rambam's view, which is shared by many other authorities, these behaviors lead to a way of thinking which is inimical to Torah. "Magical thinking" is, in fact, one of the key elements of idolatrous belief and worship.
At the same time, there were some Rabbis that maintained that the practices prohibited by the Torah are actually effective, but that Hashem forbade our involvement in them for a different reason. Most notable among proponents of this view is Nachmanides, the Ramban:
And now, know and understand regarding magic, that the Creator (may He be blessed) created everything from nothing and made the upper realms the guides of what is beneath them; and He placed the power of the earth and all that is in it in the stars and constellations according to their motion and direction, as has been demonstrated in the science of astrology...However, it was one of His great wonders, that He placed within the upper realms alternate ways, and forces by which one might change the governance of the realms beneath them...But it is the regular governance of the constellations that the Creator (blessed is He) desires, which He placed in them to begin with, and this would be the opposite. This is the secret of magic and its power, such that the Rabbis said regarding magical practices that they "contradict the Council Above"; in other words, they subvert the simple forces of nature, which is a contradiction to the upper realms to some extent. Therefore, it is proper that the Torah prohibit them so that the world will be left to its normal function and its natural state, which is the desire of the Creator...
There are many who belittle the reading of omens and say that they have no truth to them at all...But we cannot deny things that have been clearly demonstrated before witnesses.
Note that the Ramban is operating within the framework of God's Unity. He could not possibly have entertained the notion that magical activities tap into forces that are completely independent of Hashem. Rather, he believed that whatever could be accomplished through these rituals was "built in" to God's creation from the outset.
This concept must be stressed because the Ramban's position is so often misunderstood. People frequently assert that "the Ramban believed in magic", as if he acknowledged the existence of a separate realm of evil forces that could be harnessed against the will of the Creator. This perspective is not only wrong, it is heretical!
Close analysis of the words of our Rabbis offers an important clarification. Both Rambam and Ramban maintain that all of existence reflects the design and wisdom of the Almighty, and that no force can operate independently of that design. Their dispute revolves around whether the magical activities proscribed by the Torah are really effective or not.
According to the Rambam, anything scientific is ipso facto permitted. Therefore, if magical rites were actually efficacious, the Torah would have allowed them. The problem is that whatever impact they do have is only imaginary. This is why they are prohibited.
Ramban disagrees with the Rambam and asserts that not everything "real" is necessarily permitted. Activities that undermine or subvert the course of nature are forbidden, precisely because they really work. Ramban thought that the occult practices described in the Torah operated through "loopholes" in the Creation that enabled man to tamper with the Universe to an extent that is inappropriate. This is why, according to Ramban, we are not allowed to engage in them.
Genetic engineering and cloning afford us modern applications of these theories. It seems likely that the Ramban would view these procedures as unacceptable meddling with the course of nature, while the Rambam would argue that, since they have a scientific basis, they are permitted.
There is one more fundamental issue that must be explored here. From his commentary, it is clear that the Ramban's attitude toward the occult was based upon the scientific knowledge that was available to him. He felt that the power of magical practices and the reliability of astrological predictions had been confirmed experimentally. The question is - what would the Ramban say about magic, astrology, etc., today?
Modern science has systematically discredited astrology, superstition and magic. There is not a single shred of empirical evidence that supports their validity. Thus it is almost certain that, were he alive today, the Ramban would change his view of the occult and agree wholeheartedly with the Rambam.