There is a wide range of opinion that the Church allows on the issue of the corporal punishment of children, from believing that it is allowable to believing that it is not. However, the idea that it can be allowable is tempered by the principle that there must be no danger of harm to the child. In the Summa Theologica, St. Thomas Aquinas is of the opinion that corporal punishment of children by parents is allowable but states:
Hence when parents are forbidden to provoke their children to anger, they are not prohibited from striking their children for the purpose of correction, *but from inflicting blows on them without moderation *(source, emphasis added).
Moderation presumes control of one’s own emotions and control of the force that one uses. Deliberate failure to do so can indeed be sinful. Non-deliberate failure to do so may not be sinful in the moment – because knowledge and freedom of choice are necessary for sin – but this suggests that spanking is a possible occasion of sin for the person who cannot maintain control and should be avoided.
If a parent is unable to spank a child without becoming angry and inflicting blows he or she knows to be excessive to that which is necessary to address the child’s behavior, then I can only recommend finding other means of correction. A counselor may be able to suggest effective disciplinary methods that do not involve spanking. Referrals to a Catholic counselor can be obtained from the Pastoral Solutions Institute or from CatholicTherapists.com.
Parenting with Grace by Gregory K. Popcak