Motivation for Miztvot

Question

According to Bava Kamma 79b, the penalty difference between a ganav and a gazlan is that the robber does not disrespect Hashem -- he commits his crime in full view of anyone, man or God but the thief hides his action from man (showing he fears man more than God).

Is there a parallel distinction made when assessing the reward for performing mitzvot? If I obey a mitzvah only publicly is it "worth" less because it shows that I am driven by man's opinion more than God's? What if I perform it in public and in private but only out of respect for another person's sensibilities and not because Hashem commanded it - would the "reward" be any different? Could there be a difference even in whether someone is yotzei through his performance if the motivation is not driven by Hashem?

Answer 1

The Mishnah (Avos 5) teaches:

בֶּן הֵא הֵא אוֹמֵר, לְפוּם צַעֲרָא אַגְרָא

Ben He He said: According to the labor is the reward.

Most commentaries understand this as applying to all mitzvot; the more difficult it is to perform the mitzvah, the greater the reward. I think it follows that, all things being equal, a mitzvah performed in public and which gives the performer some measure of honor will be inferior in this respect when compared with a mitzvah performed privately which doesn't bring with it the added benefit of fame and glory. And the same will be true for any ulterior motive which makes it easier to perform a mitzvah. This really depends more on the motivation in each individual case and less on external factors like public or private.

Additionally, a mitzvah done for no ulterior motive carries with it an additional mitzvah of Kiddush Hashem. As Maimonides writes (M.T. Yesodei 5:10):

וְכֵן כָּל הַפּוֹרֵשׁ מֵעֲבֵרָה אוֹ עָשָׂה מִצְוָה לֹא מִפְּנֵי דָּבָר בָּעוֹלָם ... וְלֹא לְבַקֵּשׁ כָּבוֹד אֶלָּא מִפְּנֵי הַבּוֹרֵא בָּרוּךְ הוּא כִּמְנִיעַת יוֹסֵף הַצַּדִּיק עַצְמוֹ מֵאֵשֶׁת רַבּוֹ הֲרֵי זֶה מְקַדֵּשׁ אֶת הַשֵּׁם

So too if one refrains from sin, or fulfills a commandment without ulterior motive... nor in pursuit of honor, but merely for the sake of the Creator as [for example] when Joseph extricated himself from his master's wife, such a person sanctifies the Name of God.