"Please note that Calvin in his Commentary on Exodus 4:25 (post-Trent 1563) comments…'that the ceremony thus rashly performed, pleased God…. Although it [the circumcision] was improper…, it is…approved'…. If the unordained female Midianitess Zipporah's highly irregular circumcision of Moses' son was valid — how much more so, felt Calvin, are the less irregular baptisms performed by the ordained male priests of the Church of Rome!"
Dr. Thompson next cites Calvin's Institutes IV:16:9,20f . He then points out667 that Dr. Calvin himself "was baptized only once; in infancy; in the RC Church; and never again. His wife Idelette, baptized…in an Anabaptist sect in Holland, was never rebaptized by sprinkling — after her conversion to the Reformed faith and then her marriage to Calvin. Before someone calls out 'pre-Trent behavior' — let me continue with a  quotation from the delightful Calvin: