Great Dutch philosopher. He was brought up a Jew but after studying the works of all the notable philosophers of Judaism, Christianity and Islam, he abandoned organised religion for good. He was a pantheist; he rejected Cartesian dualism of the mind and body and argued instead for the existence of a single substance with both intellectual and physical attributes. He advanced many sciences (the theory of natural affects alone counts for a lot!) and was especially influential for Albert Einstein, but the way he interpreted the Holy Scriptures earnt him particular renown. He thought they should be understood via rational analysis of the text itself, not via the imaginative faculties of exegetes. He created a political theory of freedom, whereby the state is obliged to respect freedom of religion, thought and speech: nobody has the power to command languages (‘nul n’a le pouvoir de commander aux langues’), especially since people themselves have no control over what they say (‘puisque les hommes eux-mêmes ne parviennent pas à contrôler ce qu’ils disent’).