A certain monk approaches the Buddha and asks various questions: "By what is the world led? By what is it drawn along? Under the sway of what that has arisen, does it go?" The Buddha praises the questioner: "Happy is your approach" (bhaddako te ummaggo) and says that the answer to his question is "thought." "Of what sort is the man widely learned who knows the Dhamma?" "He who understands the meaning and text of the Dhamma and is set on living in accordance with it." Similarly, the man of great wisdom is he who thinks for the profit both of himself and of the whole world.
A.ii.177f. (On the title of the sutta. and the meaning of the word ummagga see GS.ii.184, n.5)