Rav Aharon Lichtenstein's Dilema
I was once walking with my family in the Beit Yisrael neighborhood, where R. Isser Zalman Meltzer used to live. For the most part, it consists of narrow alleys. We came to a corner, and found a merchant stuck there with his car. The question came up as to how to help him; it was a clear case of perika u-te’ina(helping one load or unload his burden). There were some youngsters there from the neighborhood, who judging by their looks were probably ten or eleven years old. They saw that this merchant was not wearing a kippa. So they began a whole pilpul, based on the Gemara in Pesachim(113b), about whether they should help him or not. They said, "If he walks about bareheaded, presumably he doesn’t separate terumot u-ma’asrot,so he is suspect of eating and selling untithed produce….” I wrote R. Soloveitchik (his teacher and father-in-law) a letter at that time, and told him of the incident. I ended with the comment, "Children of the age from our camp would not have known the Gemara but they would have helped him." My feeling then was: Why, Ribbon shel Olam, must this be our choice? Can’t we find children who would have helped him and still know the Gemara?Do we have to choose? I hope not; I believe not. If forced to choose, however, I would have no doubts where my loyalties lie: I prefer that they know less gemara but help him.
-(Rav Aharon Lichtenstein, By His Light, p. 249)
אמר רבי שמואל בר רב יצחק אמר רב מותר לשנאתו שנאמר (שמות כג, ה) כי תראה חמור שנאך רובץ תחת משאו מאי שונא אילימא שונא נכרי והא תניא שונא שאמרו שונא ישראל ולא שונא נכרי אלא פשיטא שונא ישראל ומי שריא למסניה והכתיב (ויקרא יט, יז) לא תשנא את אחיך בלבבך אלא דאיכא סהדי דעביד איסורא כולי עלמא נמי מיסני סני ליה מאי שנא האי אלא לאו כי האי גוונא דחזיא ביה איהו דבר ערוה
Rabbi Shmuel bar Rav Yitzḥak said that Rav said: Although one who sees another committing a sin should not testify against him by himself, he is nonetheless permitted to hate him, as it is stated: “If you see the donkey of he who hates you lying under its load” (Exodus 23:5). The Gemara clarifies this verse: What is the meaning of he who hates you mentioned in the verse? If you say it is referring to a gentile who hates you, but wasn’t it taught in a baraita that the phrase: He who hates, of which the Torah spoke, is a Jew who hates you, not a gentile who hates you? Rather, it is obvious that the verse is referring to a Jew who hates you. But is one permitted to hate a fellow Jew? But isn’t it written: “You shall not hate your brother in your heart” (Leviticus 19:17), which clearly prohibits the hatred of another Jew? Rather, perhaps you will say that the verse is referring to a situation where there are witnesses that he performed a sin. However, in that case, everyone else should also hate him. What is different about this particular person who hates him? Rather, is it not referring to a case like this, when he saw him perform a licentious matter? He is therefore permitted to hate him for his evil behavior, whereas others who are unaware of his actions may not hate him.