Early modern Jewish Europeans absolutely thought and talked about witchcraft and the witch trials. First I'll discuss Jews' involvement (voluntary or forced) in related subjects, then I'll touch on Eastern Europe (with the big problem that I do not read Polish or Lithuanian), and finally go back to one rather spectacular Western European text.

There are two related areas where there is a wealth of primary and second research. First, scholars of Jewish history have published some fascinating research on demonic possession, exorcisms, clairvoyance in Sabbateanism especially among women prophets, and early modern "magical" healing, charms, and ritual objects. As scholars enjoy pointing out, Christians interpret "Thou shall not suffer a witch to live" as "exist." Early modern Jews interpreted Exod 22:18 as "to make a living," that is, to pay for their services. Some of the really interesting sources here are rabbinic responsa to questions that might even include "under what circumstances can Jews accept the services of a Christian or Muslim exorcist?"

Second, there's been a lot of attention from all directions--including modern anthropologists studying prejudice and violence--to parallels between accusations of witchcraft and of blood libel/ritual murder. That is, the medieval and early modern Christian belief that Jews kidnapped and murdered Christian children in a perversion of the Christian-Catholic Eucharist. In records surrounding these accusations and trials, especially in German-speaking territories, we see Jews responding as a community, not just as individuals, to protect the accused and unaccused alike.

Concerning Jewish involvement in actual witchcraft trials, it seems like the best data here comes from Poland-Lithuania. This is a big problem for modern research, since until a decade ago or so, our major piece of research on witchcraft in Poland was a 1952 Stalinist propaganda piece. Right. More recent efforts have centered on overturning a lot of those myths and complicating the view of Poland as the "state without stakes" (i.e. the archival research hasn't been done/the records don't survive to get an idea of just how widespread witch hysteria was--scholars toss out "maybe 2000 people were burned or otherwise executed???" but it is rather much a guess at this point. At least one of the areas where we have good evidence of many accusations, it seems the authorities acquitted nearly everyone, but we need more research to say whether that reflects a political struggle, class divisions, views of witches, etc).

In Lithuania, though, we have a few cases of Jews as accused witches in the 18th century, and as accusers in the 17th. Unfortunately I cannot read the secondary sources here so that is all I personally have. However, if there's witness testimony surviving from those cases (and not just a recorded name), it could be a problematic but potentially rich primary source of at least some Lithuanian Jews' thoughts on witch trials.

(Problematic because medieval and early modern testimony can be very "troped"--people "followed a script," so to speak, in interpreting and thus testifying about witchcraft. That's why you can have 85,000 innocent women and 15,000 innocent men telling the same stories about witches' sabbaths and flying and killing cattle.)

As far as ideas about witches and witchcraft go, though, there is one popular text from western Europe that presents a fascinating case study. Seventeenth-century rabbi Menasseh Ben Israel was part of the Portuguese/Sephardic diaspora community in early modern Amsterdam. In 1651 or 1652, he compiled and published the Nishmat Hayyim, or Soul of Life, with an important goal: to prove the eternity of the human soul in contrast to perceived radical religious elements. One of his strategies, which we also see in some Christian works of the time, was to prove the existence of God and souls by providing evidence for the existence of demons and demonic possession of souls. And in one set of chapters, Ben Israel explicitly addresses sorcery.

As J.H. Chajes points out, Ben Israel doesn't actually share Jewish contemporaries' views of magic--he works in a thoroughly demonizing paradigm. His understanding of magic parallels Christians': magic is necessarily and inherently heresy!

And his descriptions of maleficium in action sound archly familiar. He describes pacts made with a demon, sometimes sealed in blood; transformation into animal familiars; magic-abetted journeys over long distances; murder of children; diabolical cooking concotions; flying.

This is especially noteworthy because Ben Israel has constructed this parallel to European witchcraft based on stories about Africa.

That's right. He describes "the city of Guinea in the continent of Africa" as the source for all these stories. Of course there's a layer of racist polemic here: "All types of sorcery are found there because they are blacks and their souls are from the side of the unclean."

And somehow ("somehow") Ben Israel feels justified in making this judgment despite his observations about the same thing in his own land:

Now, all of the land of Ashkenaz [the Rhineland] and Alsace, France, and other nations know the deeds of the witches, who are called in their language sagi or hexerei, and they are women who have made a pact with devils and they have a special time and meet in a certain place, in covens. There they dance and caper throughout the nights and have intercourse with satyrs, these being spirits who appear in the guise of he-goats. Every day they are arrested and interrogated. If they deny the matter, they are tried by water, for those innocent of the charge sink and are saved and redeemed, while the guilty float, and fly like birds. Thus their sentence is uniformly to be burnt, even if they are lovely maidens. Every day these trials are conducted and many books have been published on their ways and deeds.

Ben Israel has, of course, drastically overstated the prevalence and frequency of witch trials--Amsterdam absolutely had its share of witch hysteria moments, but they were quite widely spaced out. He's also wrong that a conviction for witchcraft was an automatic death sentence--fines and imprisonment were options that we know in many cases were taken, and of course there were also acquittals. (But observe--even he knows that "swimming the witch" was not supposed to be a death sentence for the innocent.)

And yet we are immediately remind that Ben Israel isn't just being racist in randomly adding the African cases with a condemnatory sweeping statement of theological anthropology, he is being racist in service of making a polemical point about Europe. (Much ethics.) Remember, his argument in this section is that souls and demons exist because demons possess souls, and souls are immortal because demons make pacts with souls for the eternal possession thereof. So Ben Israel has a big, big problem with a popular train of intellectual thought in his day:

Legal experts ask and question whether [witches] deserve death or not, for it appears in the eyes of their great sages that they do not sin in action nor gather in a place to conjoin with spirits, but on the contrary, they do not budge from their beds and merely act in their imaginations. For they have forced and compelled their minds to believe that Satan will couple with them and satisfy their desire in fornication, as he has more strength than any man in size, hardness of instruments, and prolongation of the exercise, and other types of pleasure. And it seems to them in their dream that they travel and dance with the spirits, and in the course of the imaginary intercourse, they become hot and come to ejaculation and have great pleasure, as some of them have admitted under investigation. And it is not true, but the act of spirits, worthless imagination...And according to this opinion, they are killed and burnt unjustly, for in no book of laws is there a punishment proscribed for the hidden thoughts of the heart.

That's a giant wall of quote, but in essence, Ben Israel rehearses the argument that witches aren't actually consorting with Satan and working magic. They have simply deluded themselves into believing that they are. Thus they are guilty of bad intentions, but not bad actions, and this is not a capital crime.

And Ben Israel will have none of this. For him, the centerpiece of it all is the pact with Satan or other demons, the actual handing over of one's soul to the forces of darkness. Far more than any actual nefarious deed in the world, it's the interaction with the diabolical that exists whether the alleged witch is actually flying off to a mass orgy at night or simply lying in bed thinking about it.

This is actually a very Portuguese attitude. Although there aren't very many cases where the Inquisition in Portugal went after witches (the Iberian inquisitors were much more concerned about heresy and crypto-Judaism), the few that did show almost total concentration on the intention and the agreement with the devil. I've read about one case where a woman was accused of fifty murders, but the inquisitors pretty much ignored that and were like, "So, about that conversation with the demon."

He needs all the evidence or "evidence" he can muster about demonic pacts, and he gets some of his most stomach-churning and memorable from--you guessed it--what "the sages of all nations" have told him about 'Guinea':

The blacks strike their fingers with a small knife between the flesh and the nail, and remove by the means of the horn of a male goat some blood, and write on a board how they submit themselves to a demon and work wonders.

With rumors like that, who needs Dr. Faust?