Flagellation, more especially in its masochistic form, is sometimes associated with true inversion.  Moll presents the case of a young inverted woman of 26, showing, indeed, many other minor sexual anomalies, who is sexually excited when beaten with a switch.  A whip would not do, and the blows must only be on the nates; she cannot imagine being beaten by a small woman.  She has often in this way been beaten by a friend, who should be naked at the time, and must submit afterward to cunnilinctus. (Moll, Kontraere Sexualempfindung third edition, p. 568.)

In the preceding case there were no masochistic ideas; it is likely that in such a case beating is desired largely on account of that purely physical effect to which attention has already been called.  In the same way self-beating with a switch or whip has sometimes been spontaneously discovered as a method of self-excitement preliminary to masturbation.  I am acquainted with a lady of much intellectual ability, sexually normal, who made this discovery at the age of 18, and practised it for a time.  Professor Reverdin, also, speaks of the case of a young girl under his care who, after having exhausted all the resources of her intelligence, finally discovered that the climax of enjoyment was best reached by violently whipping her own buttocks and thighs.  She had invented for this purpose a whip composed of twelve cords each of which terminated in a large chestnut-burr provided with its spines. (A.  Reverdin, Revue Medicale de la Suisse Romande, January 20, 1888, p. 17.)

FOOTNOTES: 

[107] The discipline or scourge was classed with fasting as a method of mastering the flesh and of penance.  See, e.g., Lea, History of Auricular Confession, vol. ii, p. 122.  For many centuries bishops and priests used themselves to apply the discipline to their penitents.  At first it was applied to the back; later, especially in the case of female penitents, it was frequently applied to the nates.  Moreover, partial or complete nudity came to be frequently demanded, the humiliation thereby caused being pleasant in the sight of God.

[108] Dulaure, Des Divinites Generatrices, ch. xv; Lea, History of Sacerdotal Celibacy, 3d ed., vol. ii, p. 278; Kiernan, “Asceticism as an Auto-erotism,” Alienist and Neurologist, Aug., 1911.

[109] This is the opinion of Loewenfeld, Ueber die Sexuelle Konstitution, p. 43.