Based on a Naaleh.com shiur by Rabbi Azarya Berzon
Philosophers throughout the generation have debated this question and have come up with several theories. Early Greeks put emphasis on knowledge as the key to human success in behavior and morality. The stoics believed in self-discipline and will power. The school of Epicureans taught that contentment and banishment of fear and pain were central to human existence. Judaism accepts all these ideas as worthy but there is one overpowering virtue that defines us and that is kedusha-sanctity.
“Kedoshim tiyhe ki kadosh ani“-Be holy for I am holy. The key to developing a relationship with Hashem is sanctity. There is hardly an endeavor in human behavior that is not encompassed by kedusha. Kedusha means imitating Hashem in mind and spirit and focusing our energies on that which is uplifting. One area where kedusha is stressed most is tzniut-modesty. Much emphasis has been placed by the Poskim on the halachot of yichud. A man and woman who are forbidden to each other, may not be alone in a secluded area. The laws are complex and have become even more so in contemporary society. Sociological and technological advancement such as the fact that more women have joined the workplace, adoption has become more popular, and the rise in innovations in therapy and medicine have raised many questions in halacha. There is a whole gamut of reasons why the laws of yichud need to be studied, but most compelling is that society has become so permissive and immoral.
The laws of yichud are discussed in three places in Gemara -Kiddushin, Avodah Zarah, and Sanhedrin. The Rishonim question if yichud is a Torah prohibition? The Rambam answers that it is m’divrei kabbalah because there is only an allusion to it in the Torah. For something to be m’dorayta there has to be an explicit verse telling us so. However many Rishonim counter that it is m’d’orayta How then could the Torah allow so many leniencies in different situations?
The Smag and the Sefer Hachinuch point out a verse in Vayikra that forms the base for the prohibition of yichud, “V’el isha b’nidas tumasa lo sikorov.” What does kirva mean? According to some Rishonim kirvah is yichud. There are cases when a prohibition is deliberately vague in the Torah allowing our Sages to define the parameters, which is the case here with yichud.
What is the nature of yichud d’orayta? What defines it? Yichud is a situation where a man is secluded with a woman who is forbidden to him. Is the Torah protecting the person from a more serious prohibition or is yichud in and of itself objectionable? The Ramchal writes that yichud is prohibited onto itself. This is also a machloket between Rashi and Tosfot. The Gemara in Kidushin asks, may a man be alone with a married woman whose husband is within the city limits? Rashi rules that it is prohibited while Tosfot maintains that it is permitted. The root of their disagreement is really how yichud is defined. Rashi maintains that yichud itself is an issur while Tosfot maintains that it is only to protect us from a more serious violation. Therefore according to Rashi even a split second is yichud while according to Tosfot it would need to be a longer duration.
The Piskei Teshuva rules that if the door is closed and unlocked, there is no issur yichud. However according to Rav Akiva Eiger the door or window must be open in a way that anyone can look in. The Gemara in Avodah Zarah writes that King David and his beit din enacted an issur d’rabanun of yichud that a man may not be alone with an unmarried woman. The Beit din of Hillel and Shammai ruled that yichud extends to being alone with a non-Jew too. The Mishna prohibits a man from being alone with two women. The Rashba adds that this is only d’rabanun. For yichud to be d’orayta it must be a state of perfect seclusion.
If there is a situation of yichud in a car, some poskim rule to take another woman along. Then the prohibition gets reduced m’dorayta to m’darabanun and in a car there’s less suspicion of an issur. In the presence of a young child who can serve as a chaperone, according to some Poskim between the ages of seven and nine, yichud may be permissible. Giving another man the key with the understanding that he can come in at any moment could also be a deterrent. The halacha differentiates between a man who is kosher and a paratz (one who is not careful with Jewish law). In a case of a paratz, he may not be alone even with ten women. If such a man is traveling on the road and there is a woman riding along, three men must be in the car. The same would be the case if they are alone in a secluded area or in an apartment late at night. A brother and sister may be alone in a house temporarily. They may not live together permanently.