One year ago, on Rosh Hodesh Adar 5768, I was sitting in my rabbinic class in Mercaz HaRav when a terrorist entered the yeshiva and gunned down eight students. Beyond the difficulties of dealing with such evil, the 
The encounter has put me in an emotional quandary.
encounter has put me in an emotional quandary, in that I was spared while others were not so fortunate.
On the one hand, when one's life is spared one is to rejoice, to give thanks to God (Rashi, Leviticus 6:12). On the other hand, the date of my salvation is the yahrzeit of eight martyrs, a day of national tragedy. It is a day of mourning, not rejoicing.
The conflicting nature of this day has given me no little amount of consternation. In looking for guidance, Rabbi Chaim Wasserman, sh.li.t.a., instructed me to read the last entry in the halachic work Hayei Adam, written by Rabbi Danziger (1748-1820). At the very end of the section on the rules of Purim, he writes that, like at the time of Purim when the people gave thanks to God for their salvation, so too one must make a personal "Purim" day to give thanks to God for a personal salvation.
Rabbi Danziger then details his personal story of a neighborhood fire, explaining that each and every one of his family members was badly hurt and 31 of his neighbors were killed. As a result of his salvation, he declared the day a personal Purim, an annual day of reflection and thanksgiving.
(As a point of clarification, while I feel a show of personal gratitude is in order, my situation is not identical to that of Rabbi Danziger. I was spared by not leaving my classroom too soon, however I was never in any immediate danger. Be that as it may, I do feel that, just as I felt the need to say birkat hagomel, I should also commemorate the event with some display of gratitude. The Rosh Yeshiva, Rabbi Shapira, concurred with this assessment.)
From the personal story of Rabbi Danziger we see, halacha l'maaseh, that one should commemorate the day with joy and thanksgiving for salvation even though others perished on the very same day.
Now, while Rabbi Danziger provides guidance which answers the question of action (i.e., what should I do), the inherent emotional quandary still gnaws at my conscience. This emotional quandary is the direct result, and direct expression, of what Rabbi Soloveitchik terms our "dialectical existence" - an existence defined by conflicting emotions. To address this aspect, I found Rabbi Soloveitchik's discussion (Out of the Whirlwind) of man's dialectical experience of particular importance.
The Rav explains that in order to effectively respond to the complexity of our existence, an existence that "abounds in dichotomies and contradictions," we must apply the complete table of our emotions - engaging "the 
We must apply the complete table of our emotions - engaging "the totality of our emotional life."
totality of our emotional life." Furthermore, he explains that we must realize that our emotions make up a continuum, such that every emotion "is born out of a previous emotional experience and points toward a new experience into which it will gradually pass." Finally, and perhaps most importantly for our discussion, the Rav refers to "antithetic experience awareness".
He explains that an emotional experience is made up of more than a single primal emotion, and that an experience obtains a depth of meaning when contrasted to various, even antithetical, emotions. The Rav writes that "the spectrum of emotions manifests... in an all-embracing experience. ...In each emotional experience there is the center-directed glance and the peripheral look. ...While emphasis is placed upon the central theme of one's experience, the attendant peripheral motifs are nevertheless relevant and meaningful."
Applying this to my situation, while I personally must express thanksgiving and even joy at being saved, it is critical for me to take into account the painful context of the event. Indeed, this is how all thanksgiving celebrations are to be enacted, in acknowledgment of our dialectical existence. This can be seen in the method of bringing a Thanksgiving Offering in the Temple, which was brought with matzot. Matzah is the quintessential dialectical symbol - on the one hand it is called lechem oni (bread of affliction), and on the other hand it is to remind us of our freedom in that we made it in haste and it didn't have time to rise. Matzah represents both our freedom and our affliction, both our pain and our joy.
Rabbi Soloveitchik writes: "Only in the paradoxical unity of contrasts is an emotion redeemed from its primeval qualities. Joy, for instance, is a great feeling if it is separated from its antithetic emotion, sadness, not by a sharp line, but rather by an infinite series of gradations, like the transitions in the rainbow - thus not breaking up the continuity of communication between both ends of the table of emotions. When completely bounded in and isolated from the adjacent areas of emotional activity and related to only a single existential aspect, joy forfeits its worth and significance. In such a case it turns into hilarity, an emotion which loses sight of central realities and helps man escape responsibilities. Judaism has discriminated between absurd gaiety and meaningful joy, between holelut and simchah."
The distinction between absurd gaiety and meaningful joy is discussed in the Gemara (Ber. 30b). The discussion begins with the question: What is the meaning of the psalmist's words "rejoice with trembling". The answer is given that, "in a place where there is rejoicing there must also be trembling." To substantiate this principle the story is then told of a wedding in which the rabbis over-rejoiced. The host, upon noticing this, took a very expensive glass and broke it. The rabbis immediately grew somber. In an apparent attempt to change the atmosphere, the rabbis asked their colleague to sing a song; upon which he sang, "Woe to us for we are to die. Woe to us for we are to die." No doubt the singer felt that the unrestrained joy of 
The distinction between absurd gaiety and meaningful joy is discussed in the Gemara.
the party needed to be tempered with a dose of existential reality. The Gemara then concludes:
It is forbidden for a person to fill his mouth with laughter in this world, for it says, "Then will our mouth be filled with laughter and our tongue with singing" (Psalms 126:2). When will that be? At the time when, "They shall say among the nations: 'The Lord has done great things with these.' "
Rosh Hodesh Adar is the beginning of the month of great joy, it is the beginning of the month when the enemies of the Jews sought to destroy them, but instead, the opposite occurred and the Jews overpowered their enemies (Esther 9:1). Adar is the month of contrasts, of conflicting emotions, of the world turned on its head. In such a world, we must be strong, ever realizing that we live a dialectical existence. In such a world, we must rejoice, ever knowing that the world is still filled with pain. In such a world, we must endeavor to perfect it, ever striving for that day when our mouths will be filled with laughter and our tongues with song. May we see that that day soon.