There is an obvious question which one must ask himself on Purim: why would the chachomim instruct us to get drunk? The Biur Halachah answers simply that since all of the miracles of Purim were done through wine, the commemoration of the events should be done with wine as well.
A second answer can be found in this week’s Torah reading. This week, we will read Parashat Zachor in which the Torah says “Zachor,” “remember” [what Amalek did to you], followed by “Lo Tishkach,” “do not forget.” The double language seems to be redundant; why are both necessary? It is possible to suggest that the word “Zachor” is meant to direct our attention to the use of the same word in the Aseret HaDibrot regarding Shabbat. We learn from this connection that just as we do the mitzvah of Zechirat Amaleik, the remembrance of Amalek using words, we also do the Mitzvah of Kiddush using words. Perhaps one can further the connection by noting that just as on Shabbat, we drink wine to recall the significance of the day, on Purim, when it is crucial for us to remember Amaleik, wine is also used.
This alternative is quite compatible with the Gemara (Megillah 7b) which discusses the Halachah of drinking on Purim. Rava states that there is an obligation to become intoxicated on Purim until one does not know the difference between “cursed is Haman” and “blessed is Mordechai.” The Gemara proceeds to relate a story involving Rabbah and Rabi Zeira. At their Seudat Purim, Rabbah arose and slaughtered Rabi Zeira. On the next day, Rabbah davened and Rabi Zeira was brought back to life. Perhaps Rabbah acted so radically because he became so drunk that he mixed up “cursed is Haman” with “blessed is Mordechai” and thought Rabi Zeira was Amalek, so he killed him as the Torah commands. However, according to Rabbeinu Ephraim, this story serves as a refutation to Rava’s statement to demonstrate the dreadful results of drunkenness.
The Magein Avraham (60:2) states that one fulfills the Mitzvah of Zechirat Amalek by praising Hashem with the words “LeShimcha HaGadol,” “to your great name,” in the Berachah of “Ahavah Rabbah.” If this is the case, it would explain why many other authorities believe that on Purim the mitzvah is not specifically to get drunk, but to express happiness. This would also fit perfectly with the language used by the Meiri as quoted by the Beur Halachah, who explicitly states that we should not just be happy about “Shtus” (meaningless frivolities), but out of our love of Hashem and what He did and still does for us.
We learn from this that Judaism, unlike other religions, fights evil not only by destroying it, but by smothering it in goodness, Torah, and Mitzvot. It is imperative that we keep this in mind constantly as we strive to be an Or LaGoyim (light to the nations).
-Editor's Note: For a full Halachic discussion of the obligation to drink on Purim, see Rabbi Jachter's article on this subject, which is available at www.koltorah.org and in Gray Matter (volume one pp. 234-238).