The Alter Rebbe discusses bitterness and brokenheartedness in avodat Hashem, while distinguishing them from depression and from unconstructive emotional release. The chapter is relevant for understanding why spiritual seriousness is not the same as sadness, and why empty levity has no place in divine service.
אַךְ בֶּאֱמֶת, אֵין לֵב נִשְׁבָּר וּמְרִירוּת הַנֶּפֶשׁ – עַל רִיחוּקָהּ מֵאוֹר פְּנֵי ה׳ וְהִתְלַבְּשׁוּתָהּ בְּסִטְרָא אָחֳרָא – נִקְרָאִים בְּשֵׁם ״עַצְבוּת״ כְּלָל בִּלְשׁוֹן הַקּוֹדֶשׁ, כִּי עַצְבוּת – הִיא שֶׁלִּבּוֹ מְטוּמְטָם כָּאֶבֶן וְאֵין חַיּוּת בְּלִבּוֹ, אֲבָל מְרִירוּת וְלֵב נִשְׁבָּר, אַדְּרַבָּה, הֲרֵי יֵשׁ חַיּוּת בְּלִבּוֹ לְהִתְפָּעֵל וּלְהִתְמַרְמֵר, רַק שֶׁהִיא חַיּוּת מִבְּחִינַת גְּבוּרוֹת קְדוֹשׁוֹת, וְהַשִּׂמְחָה מִבְּחִינַת חֲסָדִים, כִּי הַלֵּב – כָּלוּל מִשְׁתֵּיהֶן. וְהִנֵּה, לְעִתִּים צָרִיךְ לְעוֹרֵר בְּחִינַת גְּבוּרוֹת הַקְּדוֹשׁוֹת כְּדֵי לְהַמְתִּיק הַדִּינִים, שֶׁהֵם בְּחִינַת נֶפֶשׁ הַבַּהֲמִית וְיֵצֶר הָרָע כְּשֶׁשּׁוֹלֵט חַס וְשָׁלוֹם עַל הָאָדָם, כִּי אֵין הַדִּינִים נִמְתָּקִין אֶלָּא בְּשָׁרְשָׁן. וְלָכֵן אָמְרוּ רַבּוֹתֵינוּ־זִכְרוֹנָם־לִבְרָכָה: ״לְעוֹלָם יַרְגִּיז אָדָם יֵצֶר הַטּוֹב״, וְהַיְינוּ, בְּכָל עֵת שֶׁרוֹאֶה בְּנַפְשׁוֹ שֶׁצָּרִיךְ לְכָךְ. אַךְ שְׁעַת הַכּוֹשֶׁר, שֶׁהִיא שָׁעָה הַמְיוּחֶדֶת וּרְאוּיָה לְכָךְ לְרוֹב בְּנֵי אָדָם, הִיא בְּשָׁעָה שֶׁהוּא עָצֵב בְּלָאו הָכֵי מִמִּילֵּי דְעָלְמָא, אוֹ כָּךְ בְּלִי שׁוּם סִבָּה, אֲזַי הִיא שְׁעַת הַכּוֹשֶׁר לְהַפֵּךְ הָעֶצֶב לִהְיוֹת מִ״מָּרֵי דְחוּשְׁבָּנָא״ הַנִּזְכָּר לְעֵיל, וּלְקַיֵּים מַאֲמַר רַבּוֹתֵינוּ־זִכְרוֹנָם־לִבְרָכָה ״לְעוֹלָם יַרְגִּיז וְכוּ׳״, כַּנִּזְכָּר לְעֵיל, וּבָזֶה יִפָּטֵר מֵהָעַצְבוּת שֶׁמִּמִּילֵּי דְעָלְמָא.
In truth, however, a contrite heart and the bitterness of the soul—because of its remoteness from the light of the Divine Countenance and its being clothed in the sitra achara—are not called atzvut (dejection) in the sacred tongue, for atzvut implies that the heart is dull like a stone and is devoid of vitality. But in the case of merirut (bitterness) and a broken heart, the contrary is surely true—there is vitality in the heart fermenting agitation and bitterness, except that this vitality stems from the attribute of the holy gevurot (severity), whereas joy comes from the attribute of chasadim (kindness), for the heart is comprised of them both. Thus it is sometimes necessary to awaken the attribute of the holy gevurot in order to ameliorate the stern judgments, arising from the animal soul and evil nature, when triumphing, Heaven forfend, over man. For the stern judgments can be sweetened only at their source. Therefore the Rabbis, of blessed memory, said that “a person should always rouse the good impulse,” that is, whenever he perceives in his soul that he is in need of it. But the propitious time, which is the time specifically fitting for the majority of people, is when one is in any case troubled by mundane worries, or, simply, without apparent cause. Then is the appropriate time to transform the sadness by becoming one of those “masters of account” mentioned earlier and to act on the counsel of the Rabbis that “[a person should] always rouse…,” as has been mentioned above. Thereby will he rid himself of the dejection occasioned by mundane affairs.