Objection 1. It would seem that sobriety is not by itself a special virtue. For abstinence is concerned with both meat and drink. Now there is no special virtue about meat. Therefore neither is sobriety, which is about drink, a special virtue.
Objection 2. Further, abstinence and gluttony are about pleasures of touch as sensitive to food. Now meat and drink combine together to make food, since an animal needs a combination of wet and dry nourishment. Therefore sobriety, which is about drink, is not a. special virtue.
Objection 3. Further, just as in things pertaining to nourishment, drink is distinguished from meat, so are there various kinds of meats and of drinks. Therefore if sobriety is by itself a special virtue, seemingly there will be a special virtue corresponding to each different kind of meat or drink, which is unreasonable. Therefore it would seem that sobriety is not a special virtue.
On the contrary, Macrobius [In Somno Scip. i, 8 reckons sobriety to be a special part of temperance.
I answer that, As stated above (Question 146, Article 2), it belongs to moral virtue to safeguard the good of reason against those things which may hinder it. Hence wherever we find a special hindrance to reason, there must needs be a special virtue to remove it. Now intoxicating drink is a special kind of hindrance to the use of reason, inasmuch as it disturbs the brain by its fumes. Wherefore in order to remove this hindrance to reason a special virtue, which is sobriety, is requisite.
Reply to Objection 1. Meat and drink are alike capable of hindering the good of reason, by embroiling the reason with immoderate pleasure: and in this respect abstinence is about both meat and drink alike. But intoxicating drink is a special kind of hindrance, as stated above, wherefore it requires a special virtue.
Reply to Objection 2. The virtue of abstinence is about meat and drink, considered, not as food but as a hindrance to reason. Hence it does not follow that special kinds of virtue correspond to different kinds of food.
Reply to Objection 3. In all intoxicating drinks there is one kind of hindrance to the use of reason: so that the difference of drinks bears an accidental relation to virtue. Hence this difference does not call for a difference of virtue. The same applies to the difference of meats.
Source: Summa Theologica (New Advent)