Shakespeare set his play of King Lear in pre-Christian England, so it’s no surprise that Lear in his rage appeals to Nature–“Hear, Nature, hear, dear goddess, hear!” (1.4.268)–and swears by “the operation of the orbs” (1.1.112).

Does this make him a pagan by Halachic standards? Of course there’s no single definitive answer since experts disagree. Still, it’s always intriguing to see how much  Talmud authorities knew about and perhaps believed in “the operation of the orbs.”

One example of this is the discussion of bloodletting in the Babylonian Talmud, Shabbat 129b. By modern medical standards, bloodletting seems like a stupid idea, but the antiquity and persistence of the practice should serve as a warning for our own fixed ideas about good health. Imagine letting someone with a scalpel and basin pierce a vein in person after person, presumably without anesthetic or antisepsis.

The Talmud has a long discussion about what to eat or drink after the procedure, how often to do it, and days to avoid. Letting blood is a bit of a risk, so don’t do it on a Monday or Thursday: the Heavenly Court and earthly court both meet on those days, so you’re more likely to be taken to task for your failings.

Tuesdays are out, too, because Mars has influence during the even hours on a Tuesday.

What, they believed in astrology? Oh sure, just as we believe in cholesterol. The seven planets–Saturn, Jupiter, Mars, the sun, Venus, Mercury and the moon–have their Hebrew names. Each planet has influence for an hour at a time (i.e., one-twelfth of the night or one-twelfth of the daylight). This started when the planets were put in position on the fourth day of Creation, Tuesday night: the first hour was Saturn’s, then came Jupiter, then Mars. Mars is a bad boy and wreaks havoc.

What’s more, elsewhere (Pesachim 110b) we learn that pairs, or even numbers, are susceptible to demonic influences.

Now, nobody lets blood in the dark, so don’t worry about any of this until daylight.

But if it’s a daylight Mars hour that’s also an even hour, you shouldn’t take any risks. Don’t have your blood let on a Tuesday, when Mars has the eighth hour. What about Wednesday, when Mars has the twelfth hour? Oh, that’s so close to nightfall you needn’t worry so much. What about Friday, when Mars has the sixth hour? Well, people commonly go and let blood before Shabbat, so it’s a good thing the Psalmist says that God protects stupid people (116:6).

The Talmud adds other days when you shouldn’t let blood.

Maybe the Talmud is toying with contemporary astrology and really thinks that bloodletting is always stupid, or maybe the Talmud accepts the astrological assumptions.

So just in case, be sure to wear your bike helmet on a Tuesday, bring an umbrella, don’t walk under a ladder, and don’t step on a Mars Bar wrapper, because that’s bad luck for sure.

This is superstition, not idolatry. I guess it’s okay to let astrology guide your life, so long as you don’t worship your orrery.

I think the ban on risky activities on Tuesday should be called the Mars Bar.

And Kol Hakavod to the ArtScroll Talmud editors for explaining the theory of planetary influence over the hours.