The Talmud says (Sotah 3a): “A person does not commit a sin unless a spirit of insanity overtakes him.” A person who is insane is exempt from liability since he cannot be held accountable for his behavior. Why, then, is a person punished for transgressions? The Gemara clearly states the person is definitely insane at the time of sin!
The Gemara (Nedarim 9b) tells of a very handsome young man who vowed to become a Nazirite. For the period expressed in his vow he would abstain from wine and grape products, he would be forbidden to shave or cut his hair and he had to stay spiritually pure by avoiding proximity to dead bodies. At the end of his vow he had to undergo a process that included shaving off his hair and bringing a sacrificial animal, part of which is given to the Kohen to eat. Shimon Hatzaddik — a Kohen — never partook of his share of the offering of a nazir except once — in the case of this particular young man.
“Why did such a good-looking young man with such beautiful hair make a voluntary vow that would eventually require him to shave off his locks?” Shimon Hatzaddik inquired.
“I am a simple shepherd and one day I saw my reflection in the lake. The Evil Inclination started to work on me to use my beauty for sin. At that moment I immediately accepted the vows of a Nazirite to protect myself from sin.”
Upon hearing his explanation, Rabi Shimon kissed him on the head and said: “There should be many more Nazirites — for the sake of Heaven — like you.”
This young man knew that his hair could lead to sin and so he swore to shave it off. He anticipated the danger and protected himself from his own baser instincts.
This reveals the answer to our question. Even though a person may be considered insane at the time of sin, he is still held accountable for his behavior and the lack of caution previous to the act. Should a person enter an environment that is spiritually dangerous and then, chas v’shalom, fall victim to the circumstances, the individual is held responsible for his actions. For example, if a person drank too much alcohol and then harmed another while driving drunk, “I was drunk and didn’t know what I was doing” is no excuse. “You should not have gotten drunk in the first place,” would be the judge’s response.
We live in a world where many situations that are considered acceptable for social or business purposes are actually spiritually dangerous. We are expected to stay away from situations and environments that can lead to disaster. If one does not — despite the fact that “A man does not sin unless he is temporarily insane” — one is held responsible for exposing oneself to the trap into which one fell.
May we be as the wise one described by our Sages: “Chacham einav b’rosho — the wise one has eyes in his head [to see the eventual results of his actions].” (Kohelet 2:14):