AMBITION. - Etymologically it derives from the Latin word ambire, "to go around" or to canvass for honors or offices.
In a broad sense, quite frequent in popular language, a. means the desire to assert oneself, to attain honors, to reach positions of responsibility. In this sense one customarily speaks of noble and holy a.
In a narrower sense, and the only one that occurs in moral theology, it means an disordered desire and an unbridled pursuit of honors and offices. Understood thus, it is born of pride. St. Thomas in the Sum. Theol., 2ᵃ-2ᵇ, q. 131, a. 1, defines it thus: "A. is a sin by which honor is pursued in a disordered manner, either because one does not deserve it, or because one does not refer it to God but solely to oneself."
A., as St. Thomas already notes in the same article, can manifest itself in three ways, according to the diversity of the disordered pursuit and craving for honors, offices, and dignities: 1) by desiring dignities and honors greater than those that can befit the one desiring them; 2) by seeking glory and honors through illicit actions or means: for example, through scheming, uprisings, rebellions, etc.; 3) by seeking honors with a veritable offense against God. This vice can even reach the point of being a grave sin, as in the following cases: a) when the ambitious person places his ultimate end in honors; b) when he seeks honors with grave harm to his neighbor or to the detriment of God's honor; c) when he seeks and obtains honors through gravely illicit means.