The story is told twice over, with Shammai first, and the contrast is the point. A gentile comes to Shammai asking to be taught the whole Torah while standing on one foot, and Shammai drives him off with the measuring rod in his hand. He goes to Hillel, who converts him and says: what is hateful to you, do not do to your fellow — that is the whole Torah, the rest is its commentary; go and learn it. The formulation is negative, which commentators have argued about for centuries: it demands restraint rather than initiative, and it is enforceable in a way that love is not. The second half is the part that gets dropped in quotation and matters more — the sentence does not release anyone from the other 612 commandments, it tells them what the commandments are for. The Talmud's decision to record Shammai's behaviour, unflatteringly and without comment, is itself characteristic.