Is human behavior primarily the product of nature or nurture? Ask the question this way and you invite an overly simplistic answer.
Certainly our genes program at least some aspects of our behavior. And certainly every one of us learns habits and attitudes from others as we grow. Is the source of our actions, then, a complex interplay of nature and nurture, perhaps?
If any scientist succeeds in formulating a complete explanation for the mechanisms of human behavior in terms of both genes and experience, that would produce a revolution in the criminal justice system and, incidentally, in most religious traditions.
Such an explanation would leave no room for responsibility — because if genetics and formative experiences determine how a person behaves, then it's unfair to hold that person responsible for inheriting certain genes at birth, and/or for enduring certain formative experiences.
Determinists nowadays hope to develop enough scientific knowledge about human behavior to attack the idea of responsibility. Determinists in the ancient world used theological arguments, one of which stems from the Bible itself, as Rabbi Yohannan notes: Heretics might use the words from this week's reading, "I will harden the heart of Pharaoh" (Exodus 7:3) to claim that Pharaoh would have no opportunity to repent.
Rabbi Shimon ben Lakish takes issue with this view. Nothing in this passage supports that heretical, deterministic reading, he argues. Rather, God warns a person one, two, three times, and if the person continues in his transgressions, then He locks the heart closed against repentance (Shemot Rabbah 13:3).
Rabbi Shimon has read carefully. God warns Moses not to expect Pharaoh to agree quickly to the demands that he send the Hebrews out of his land, for "I will harden the heart of Pharaoh" (Exodus 7:2-3). Pharaoh, it seems, does not control his own heart.
But throughout this week's reading, Pharaoh does control his own heart. Moses and Aaron begin their first encounter with Pharaoh by presenting him with a staff that, by apparent magic, transforms into a snake. Perhaps shaken by this astounding sight, Pharaoh watches his own magicians turn their staffs into snakes, and his heart becomes strong "as God had said"(Exodus 7:13). It does not seem to happen "as God had said"; no intervention has occurred. Pharaoh controls his own "stubborn" heart (Exodus 7:14).
After seeing that his magicians can duplicate the effects of the first plague, Pharaoh again makes his heart strong (Exodus 7:22), so he does not take Moses and Aaron to heart (7:23). After the second plague, when frogs infesting Egypt have died, Pharaoh makes his heart stubborn (Exodus 8:10); and after the fourth plague, Pharaoh again makes his heart stubborn and does not send out the Hebrews (Exodus 8: 28).
In the last verses of this week's Torah reading, Pharaoh sees that the plague of hail has stopped, and his heart stays both strong and stubborn, and so he does not send the Hebrews from Egypt (Exodus 9:34-35). In every instance in this week's reading, Pharaoh controls his own heart.
But everything looks different in next week's Torah reading: God takes responsibility for strengthening Pharaoh's heart in the first verse (Exodus 10:1). Perhaps this explains the seemingly arbitrary placement of the break between the two readings, cutting into the middle of the story of the plagues. From now on, God, and not Pharaoh, strengthens Pharaoh's heart (Exodus 10:20, 27; 11:10; 14:4). From now on, Pharaoh has lost control.
The ancient rabbis believed in free will. We can control our actions, within limits. And we reset those limits every time we act. Every time we harden our hearts, every time we close our ears to the voice of conscience or shut our eyes to the teachings of the Torah, we make it a little harder for ourselves to do better the next time.
The evil that we do has consequences for us. Eventually, we reach the terrible point where some good deeds, available to us by our nature and by our education, become impossible to us by force of habit. Let us rather open our hearts, and make ourselves more capable of goodness.