Marx doesn’t use the word ‘capitalism’. The term never occurs in the finished first part of Das Kapital. (I checked this by doing a word search and found it three times, every time an apparent mistranslation or loose use of the German plural Kapitals – in German he never talks of Kapitalismus.) Since he is widely, and accurately, seen as capitalism’s greatest critic, this is quite an omission. The terms he preferred were ‘political economy’ and ‘bourgeois political economy’, which he saw as encompassing everything from property rights to our contemporary idea of human rights to the very conception of the independent autonomous individual.