Good Habits and Their Connections
Summa Theologiae I-II, qq. 55-70
Having begun the prima secundæ partis of the Summa theologiæ with a treatise on happiness as the final end of human life (1-5), followed by treatises on human actions (6-21) and passions (22-48) by which man either approaches or falls away from his beatitude, St. Thomas moves to consider next the principles of human acts, first intrinsic principles and then extrinsic. The intrinsic principles are powers and habits, but since the human powers (intellectual and appetitive) were already dealt with in the prima pars St. Thomas restricts himself here to a treatise on habits (49-89), which is followed by treatises on the extrinsic principles, namely law (90-108) and grace (109-114). The treatise on habits begins with a general consideration (49-54), and then moves to treat of particulars, which are divided between good habits (55-70) and bad habits (71-89). It is with good habits that we are concerned here, "which are virtues and other things adjoined to them, namely gifts, beatitudes, and fruits," and especially with the connections between them.
Read on via the link on the sidebar.