"The man who deprived seventeenth-century metaphysics and metaphysics in general of all credit in the domain of theory was Pierre Bayle. His weapon was scepticism, which he forged out of metaphysics’ own magic formulas. He himself proceeded at first from Cartesian metaphysics. Just as Feuerbach by combating speculative theology was driven further to combat speculative philosophy, precisely because he recognised in speculation the last drop of theology, because he had to force theology to retreat from pseudo-science to crude, repulsive faith, so Bayle too was driven by religious doubt to doubt about the metaphysics which was the prop of that faith. He therefore critically investigated metaphysics in its entire historical development. He became its historian in order to write the history of its death. He refuted chiefly Spinoza and Leibniz.  Pierre Bayle not only prepared the reception of materialism and of the philosophy of common sense in France by shattering metaphysics with his scepticism. He heralded the atheistic society which was soon to come into existence by proving that a society consisting only of atheists is possible, that an atheist can be a man worthy of respect, and that it is not by atheism but by superstition and idolatry that man debases himself.  To quote a French writer, Pierre Bayle was 'the last metaphysician in the sense of the seventeenth century and the first philosopher in the sense of the eighteenth century.' "

--Karl Marx, The Holy Family, VI.3.d

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--Richard H. Popkin, Dictionary, trans., intro., xi.

"Shelf counts of private libraries from the eighteenth century show the Dictionnaire overwhelming anything from the distant competition of Locke, Newton, Voltaire, and Rousseau."

--Thomas M. Lennon, Reading Bayle, 7.

"It doesn't look like philosophy.  It is lewd, loud, long, rambling, and very, very funny.  It never sticks to a point.  It interrupts itself with endless digression.  It often seems blithely ad hominem, offering disquisitions that cannot decide whether they are biographies of persons whose names are now forgotten or argument about questions that still perplex us.  But Bayle's Historical and Critical Dictionary is breathtakingly sharp, often unanswerable, and full of the air of excitement which is all that gives life to intellectual debate, and that can be sensed centuries later..."

--Susan Neiman, Evil in Modern Thought, 116.

"Why do professional philosophers spend so much time on Descartes and so little time on Pierre Bayle, when Bayle was clearly the better philosopher?  I hope the real answer is not that Bayle wrote too much that is too hard to survey and synthesize, whereas Descartes wrote short works that are easy to teach to undergraduates."

--John Christian Laursen, Journal of the History of Philosophy 39:1 (Jan. 2001), 146.