The third man was Hippolytus, who was a scholarly man more than the other two, and who continued the polemics against/Gnostic movement in exegetic works and church-historical works. His refutation of the heresies is already history, more than the life-and-death struggle as in Irenaeus and Tertullian.

So we have these three men, who saw the situation of the early Church. It’s important for Protestants to see how early most fundamentals of the Roman system were already present in the third century.