Gottfried Leibniz wrote to Louis Bourguet in defense of Leeuwenhoek, "to whom the public owes thanks. ... It is not right to despise him."

April 3, 1716

Leibniz replied to Bourguet's objections to Leeuwenhoek's ideas about the role of sperm by offering five points of refutation.

He ended with a sixth. "6th in all, let's not treat a man like Mr. Leeuwenhoek badly, to whom the public owes thanks for the pains he took in his research. It is very permissible to oppose his sentiment, and I am glad that one does so, but it is not right to despise him."


Gothofredi Guillelmi Leibnitii, ... Opera omnia, nunc primum collecta, in classes distributa, praefationibus & indicibus exornata, studio Ludovici Dutens. Tomus primus sextus Tomus secundus, in duas partes distributus, quarum 1. continet logicam & metaphysicam; 2. physicam generalem, chymiam, medicinam, botanicam, historiam natu

Six Letters from Mr. Leibniz to Mr. Bourguet, p. 330