Why is "doing righteous deeds" not a pillar of Islam?

Doing righteous deeds is mentioned a zillion times in the Qur'an, e.g.: > And give good tidings to those who believe and do righteous deeds that they will have gardens [in Paradise] beneath which rivers flow. ... -- Qur'an 2:25 > > ...those [among them] who believed in Allah and the Last Day and did righteousness - will have their reward with their Lord, and no fear will there be concerning them, nor will they grieve. -- Qur'an 2:62 > > But they who believe and do righteous deeds - those are the companions of Paradise; they will abide therein eternally. -- Qur'an 2:82 Indeed, on reading the Qur'an, I considered it to among the most important take-home lessons. Instruction to do good deeds occurs with frequency comparable to that of instructions to pray (and they often come together). It seems strange to me that doing good deeds is not, as a result, listed as a pillar of Islam . **Question**: Why is "doing righteous deeds" not a pillar of Islam? I'm not sure how the pillars are determined, and there's a difference between Sunni and Shia pillars (according to Wikipedia). It could possibly be part of "enjoining what is right ", although I'm not clear on this.