Whether fasting is an act of abstinence?

❌ Objection 1 : It would seem that fasting is not an act of abstinence. For Jerome [*The quotation is from the Ordinary Gloss, where the reference is lacking] commenting on Mt. 17:20, "This kind of devil" says: "To fast is to abstain not only from food but also from all manner of lusts." Now this belongs to every virtue. Therefore fasting is not exclusively an act of abstinence.

❌ Objection 2 : Further, Gregory says in a Lenten Homily (xvi in Evang.) that "the Lenten fast is a tithe of the whole year." Now paying tithes is an act of religion, as stated above (Question [87], Article [1]). Therefore fasting is an act of religion and not of abstinence.

❌ Objection 3 : Further, abstinence is a part of temperance, as stated above (Questions [143],146, Article [1], ad 3). Now temperance is condivided with fortitude, to which it belongs to endure hardships, and this seems very applicable to fasting. Therefore fasting is not an act of abstinence.