Gregory the Great — as excerpted in the Catena Aurea on Luke 18:9-14

“(23. Mor. c. 6.) There are different shapes in which the pride of self-confident men presents itself; when they imagine that either the good in them is of themselves; or when believing it is given them from above, that they have received it for their own merits; or at any rate when they boast that they have that which they have not. Or lastly, when despising others they aim at appearing singular in the possession of that which they have. And in this respect the Pharisee awards to himself especially the merit of good works.”