Thomas Aquinas

“ Whether it is opposed to magnanimity by excess?
Art. 1 - Whether ambition is a sin? Objection 1: It seems that ambition is not a sin. For ambition denotes the desire of honor. Now honor is in itself a good thing, and the greatest of external goods: wherefore those who care not for honor are reproved. Therefore ambition is not a sin; rather is it something deserving of praise, in so far as a good is laudably desired.
Objection 2: Further, anyone may, without sin, desire what is due to him as a reward. ”

“ The second point that calls for observation is that the thing in which man excels is given to him by God, that he may profit others thereby: wherefore a man ought so far to be pleased that others bear witness to his excellence, as this enables him to profit others.
Now the desire of honor may be inordinate in three ways. ”

“ The desire for good should be regulated according to reason, and if it exceed this rule it will be sinful. In this way it is sinful to desire honor in disaccord with the order of reason. Now those are reproved who care not for honor in accordance with reason's dictate that they should avoid what is contrary to honor. ”

“ Wherefore Sallust says (Catilin.) that "the good as well as the wicked covet honors for themselves, but the one," i.e. the good, "go about it in the right way," whereas "the other," i.e. the wicked, "through lack of the good arts, make use of deceit and falsehood." ”