הַשֵּׂכֶל וְהַהִתְפַּעֲלוּת שְׁנֵי עוֹלָמוֹת הֵם

Intellect and emotional enthusiasm are two distinct realms:

עוֹלָם קַר וּמְיוּשָּׁב, וְעוֹלָם רוֹתֵחַ וּמְבוֹהָל

one is cool and settled, the other is seething and frenetic.

וְזֹאת הִיא עֲבוֹדַת הָאָדָם לְחַבְּרָם לִהְיוֹת לַאֲחָדִים

Man’s task is to fuse these two realms into one.

וְאָז הַבֶּהָלָה נֶהְפֶּכֶת לִשְׁאִיפָה

At that point, the frenetic energy is transformed into aspiration, 

וְהַשֵּׂכֶל — לְמוֹרֶה דֶרֶךְ בְּחַיִּים שֶׁל עֲבוֹדָה וּפוֹעַל

and the intellect becomes a guide for a life of Divine service and action.

Text and Translation courtesy of Sichos in English