Melancholy/Sloth

Sloth seeks undue rest in so far as it spurns the Divine good

Sloth is not an aversion of the mind from any spiritual good, but from the Divine good, to which the mind is obliged to adhere.

He is sorry to have to do something for God’s sake.

Evil in itself (sadness in reaction to the highest goods – God’s good) and evil in its effects (keeps us from performing acts of good).

Scriptural/Doctoral

• St. John Damascene (De Fide Orth. ii, 14) is an oppressive sorrow, which, to wit, so weighs upon man’s mind, that he wants to do nothing.
• “A paralysis of the soul, a slackness of mind, a neglect of religious exercises, a hostility to vows taken.” St. John Climacus

Daughters

• malice: The struggle against spiritual goods that cause sorrow sometimes extends to the spiritual goods themselves, when a man goes so far as to detest them. Not happy about the spiritual goods.
• spite: The struggle against spiritual goods that cause sorrow is sometimes with men who lead others to spiritual goods. Not happy about those who lead others to spiritual goods, or the means to the spiritual goods. A kind of indignation.
• faint-heartedness: avoidance of those goods which are the means to the end, in matters of difficulty which come under the counsel
• despair: the result of avoiding spiritual goods
• sluggishness in regard to the commandments: keeping the Sabbath holy, honoring father and mother
• wandering of the mind after unlawful things: when a person has recourse to eternal objects of pleasure; so apathetic about spiritual goods I am easily distracted 

Self-examination from Episcopalian St. Augustine Prayer book (not exactly Thomistic, but useful)

SLOTH: Sloth is the refusal to respond to our opportunities for growth, service or sacrifice.

Laziness

• Indolence in performing spiritual, mental, or physical duties, or neglect of family, business or social obligations.
• Procrastination of disliked tasks.
• Busyness or triviality to avoid more important commitments.
• Devotion of excessive time to rest, recreation. or amusement.

Indifference

• Unconcern over injustice to others, especially that caused by currently accepted social standards; or unmindfulness of the suffering of the world.
• Failure to become adequately informed on both sides of contemporary issues or on the Christian principles involved.
• Ignoring the needy, lonely or unpopular person in our own or the parish family, or in the neighborhood; or unwillingness to minister to them.
• Insufficient attention to the religious and other needs of our family.