He also spent several days in intense discussion with Spinoza , who had just completed his masterwork , the Ethics .
On the journey from London to Hanover , Leibniz stopped in The Hague where he met van Leeuwenhoek , the discoverer of microorganisms .
Leibniz also spent several days in intense discussion with Spinoza , who had just completed Leibniz 's masterwork , the Ethics .
On the journey from London to Hanover , Leibniz stopped in The Hague where he met van Leeuwenhoek , the discoverer of microorganisms .