An apostle of tolerance
To the philosophers of the Age of Reason, Luther appears as a "violent and forceful man, and moreover very vain and very full of himself" (Encyclopedia of Diderot and Alembert, 1765).
In his "Letter on the Germans" (1767), Voltaire praises the "moderate and tolerant" character of Melanchthon as opposed to a terrible Luther. But, he soon finds that the tolerance of Melanchthon in religion was considered by some of his contemporaries as being the consequence of an absence of firm convictions, even of a certain indifference. Accusing him of inconstancy, he identified him with Protée, the changeable and indiscernible marine god of Greek mythology. Instead of being "the Neptune who retains the ardour of the winds " - that is the one who calms Germany by introducing religious tolerance - Melanchthon becomes, in the eyes of some, the "Protée of Germany", the one who changes too often his opinions, who is not solid enough to bring about success.
As for the criticism of Melanchthon's doubt, even scepticism, Bayle considers "that one exaggerates things", especially in anti-Protestant works. The conclusion of his article on Melanchthon in the historic and critical Dictionary is surprising : it is exactly Melanchthon's learning and erudition, his largess and his moderation that lead him to discover the truth and the fault in the opinions of those who quarrel with him and who prevent him from being absolutely firm in his own opinions. The philosopher can then come to admire Melanchthon : "(...) If some Founder wishes that his followers work successfully on the extension and on the distribution of its ideas, he has to wish that they are of a will to give up nothing." As the victory of one religion over another is established on the obstinacy of its leader, Melanchthon could not but fail.
The idea of Bayle, according to which the success of a religion does not depend on wise and tolerant theologians, but on intoxicated and intolerant leaders, announces the criticism of religion formulated by Feuerbach, Nietzsche and Marx.