The struggle between Moses and Pharaoh takes place on two fronts. First, there is the political campaign to free the Israelites from Egyptian bondage, bringing an end to hundreds of years of servitude. But then there is also the spiritual battle to convince Pharaoh and the Egyptians of God’s preeminence. Were the exodus a story of political liberation alone, there would have been no need for ten plagues or the hardening of Pharaoh’s heart – God could have simply struck the Egyptians with a devastating pandemic that would have killed them all off, leaving the Israelites to go free. The purpose of the ten plagues, as God explicitly tells Moses in this week’s parsha, is to “multiply My signs and marvels in the land of Egypt” (Exodus 7:3) so that Pharaoh and all the Egyptians will learn to recognize the hand of God in the world. Surprisingly, one of the significant turning points in this spiritual battle is the plague of lice – it is these tiny critters that first begin to convince the Egyptians of God’s supremacy.

The plague of lice is the first divine sign that the Egyptians recognize as a miracle and not magic. Previously, when Aaron converted his rod into a snake, turned the Nile to blood and summoned the frogs, Pharaoh’s magicians were quick to replicate these special effects. But when Moses and Aaron make dust into lice, the Egyptians’ spells prove ineffectual. They turn to Pharaoh and pronounce, “This is the finger of God” (Exodus 8:15)– a phrase that appears in only one other context in the Torah, to describe the two tablets inscribed with the Ten Commandments (Exodus 31:18). For the Egyptians—albeit not for Pharaoh, whose heart God has hardened—the evidence of God’s hand in the world seems rock-solid and they are forced to admit defeat, at least on the spiritual front.

Why is it the plague of lice that stumps the Egyptian magicians? The Torah states that the lice were created from dust – God instructs Moses to tell Aaron, “Hold out your rod and strike the dust of the earth, and it shall turn to lice throughout Egypt” (Exodus 8:12). Adam, too, was created from the dust of the earth, suggesting perhaps that this plague was so effective because the ability to create life from dust is the province of God alone. The Talmud offers another answer, which appears amidst a discussion of magic and witchcraft. Rabbi Eliezer, in discussing the plague of lice, explains that “a demon cannot create an entity smaller than a barley grain” (Sanhedrin 67a). According to this understanding, the Egyptian magicians were using demons to perform their magical feats. But demons cannot create anything as small as lice, and thus the Egyptian magicians were unable to replicate the third plague and could only throw up their arms.

Demons may not be able to create anything tiny, but they themselves are miniscule – at least according to the Talmudic worldview. The rabbis in tractate Berakhot (6a) explain that demons cannot be seen by the naked eye – to see them, one must take the placenta of a black cat, burn it to ashes, and place it on one’s eyes. But Abba Binyamin cautions that if the eye were able to see them, no creature would be able to withstand their abundance and ubiquity. And Rav Huna adds that each individual has a thousand demons to his left and a thousand to his right at all times. In a sense, the demons of the Talmud are not unlike the germs of our modern scientific worldview – they are microscopic entities that we cannot see with the naked eye, but whose existence we nonetheless posit.

Just as we maintain that proper hygiene can mitigate the harmful effect of germs, the Talmudic rabbis believed that proper conduct could mitigate the harmful effect of demons and other magical forces. The Talmud (Sanhedrin 67b) relates that a certain woman once tried to gather the dust from under Rabbi Hanina’s feet so as to cast a spell upon him. Rabbi Hanina told her to go ahead, insisting that he was not concerned because, as it says in the Torah, “there is no one besides Him” (Deuteronomy 4:35). The rabbis question whether there are indeed no other powers in the world. They resolve that magic is real, but it had no effect on Rabbi Hanina on account of his righteousness.

As the long arc of the history of science reminds us, belief in demons and germs—and belief in anything we cannot see—requires a leap of faith. I recall a cartoon that hung on the wall of my optometrist’s office when I was a bespectacled adolescent: “Dear God,” it said under a picture of a boy wearing a new pair of glasses, “Now that I have my glasses, I will finally be able to see you.” Indeed, perhaps the more pertinent question is not whether we can catch sight of demons, but whether we can recognize the hand of God. For the Egyptian magicians, this recognition followed the plague of lice, which makes sense: Lice are nearly invisible, and yet they cause so much distress that even the greatest skeptic would be convinced of their existence. For the rest of us, hopefully it will not take lice or any plague or pandemic to come to know God.

This past year has been a reminder that while viruses and germs are an inevitable part of our world, the decisions we make on the global, national, and individual levels can help curb their devastating impact. May we learn to act righteously and responsibly so that even when we cannot eradicate the harmful forces that threaten us, we can nonetheless ensure that we are doing our part to make the world a safer and healthier place.