What Can We Learn from Hugo Klapproth: the Sola Scriptura Doctrine is Wrong The publication of Hugo Klapproth’s work, Letters to a Protestant Friend (The Remnant Press, 2022), represents an editorial event that can help us acquire a deep understanding of the mentality and constellation of values of a pre-conciliar Catholic. And not just any Catholic, but a convert from Lutheranism who dedicated his life to defending and transmitting the truths of Christian Revelation. Klapproth’s book is not only a highly useful read but also a source of inspiration that urges us to follow in the author’s footsteps to rediscover...