Mark Twain was one of the great writers of American literature, and surely one of the funniest. He was also a famously obscene conversationalist. Helen Keller reports being shocked by how many vulgarities Twain used in everyday speech. Twain’s wife devised a strategy to cure her husband of this tendency: one day, she surprised him by letting loose a stream of curses herself to show him how it sounded.

“Honey,” said Twain, “You have the words, but you ain’t got the music.”

In Jewish tradition, there are words one is not supposed to say. In this week’s Torah portion, we are told the blasphemer should be put to death (Leviticus 24:16). That words could be fatal was taken very seriously.

The tale of Judaism and blasphemy is more complicated than it may appear: about the words and the music.

In the Talmud, the rabbis posit that one who hears blasphemy should tear his garment. Then, Rabbi Hiyya adds: “One who hears a mention of God’s name in a blasphemous context nowadays is not obligated to make a tear, as if you do not say so, the entire garment will be full of tears” (Sanhedrin 60a). In other words, blasphemy, from being a rare breach, had become rampant.

Building on biblical precedent, the rabbis were not slow to challenge God. Making a play on the verse, “Who is like You among the gods?” (elim) the school of Rabbi Yishmael taught, “Who is like You among the mute? (illemim)” (Gittin 56b). God does have a disconcerting habit of not speaking even when the Divine voice seems needed. Still, labeling God as silent is pretty daring, and could certainly be seen by some as blasphemy.

Listening to objectionable speech is part of the natural linguistic immune system. In the same way that letting kids play in dirty fields builds up their resistance, understanding the force of words while upholding freedom of speech teaches us how to grapple with ideas of all kinds. A free society takes great care with what it censors. Remember that the Talmudic practice was to preserve the rejected as well as the accepted opinions.

After all, the central declaration of the prayer service is not to speak, but to listen.