Johann Friedrich Stapfer dealt with several kinds of error in his Institutiones theologiae polemicae. In identifying the basic ideas of each heresy he sought to delineate its proton pseudos or false fundamental. He then could direct the force of his argument against this primary hypothesis of each heresy.
"When he turns to heretics, Stapfer recognises...fundamental errors that mirror, like a 'bad eminence,' the fundamental articles of the true faith. Thus, papists accept revelation and reason but hold as proton pseudos the supremacy of the pope which leads to the founding of doctrine on an infallible church rather than on the Lordship of Christ. The Pelagian proton pseudos, that fallen man can adequately obey the Law, stands over against the church's insistence on the necesssity of grace."
Richard Muller, PRRD vol. 1 Prolegmena to Theology, p. 423-4