Every Man Must Fast, Natural Law of Creation

Memento homo...

As we approach the holy season of Lent it is good to recall that fasting, "the primal form of all asceticism," "...is a commandment of the natural moral law."

"On Fasting" in Joseph Pieper, The Four Cardinal Virtues, Notre Dame, Indiana: Notre Dame University Press, 1966, 181, 182.


Because "fasting is useful as atoning for and preventing sin, and as raising the mind to spiritual things,...everyone is bound by the natural dictate of reason to practice fasting as far as it is necessary for these purposes.

"Wherefore fasting in general is a matter of precept of the natural law, while the fixing of the time and manner of fasting as becoming and profitable to the Christian people, is a matter of precept of positive law established by ecclesiastical authority:

the latter is the Church fast,
the former is the fast prescribed by nature."

Saint Thomas Aquinas, Summa Theologica, II-II, Q. 147, a. 3, c.


Pieper explains the superior reason for fasting, "as raising the mind to spiritual things" to participate in the cross of Christ in order to glory with Him in his resurrection. Ibid. 183. Note that Aquinas mentions above three reasons fasting is necessary: 1) as atonement for sin, 2) as preventing sin, and 3) as raising the mind to spiritual things. Cf. Summa Theologica, II-II, Q. 147, a. 1, c.

Note also the words of exhortation of the USCCB in the 1966 pastoral letter "On Penance and Abstinence," "[W]e hope that the observance of Lent as the principal season of penance in the Christian year will be intensified...Wherefore, we ask, urgently and prayerfully, that we, as people of God, make of the entire lenten season a period of special penitential observance... For all [the] weekdays of Lent [in addition to what is now required], we strongly recommend participation in daily Mass and a self-imposed observance of fasting..."

The Traditional Lenten Fast