A series of lectures by Robert Paul Wolff on the thought of Karl Marx:
[youtube https://www.youtube.com/watch?v=35cr_whPC88&w=640&h=360]
[youtube https://www.youtube.com/watch?v=Jiep5AYcsoA&w=640&h=360]
[youtube https://www.youtube.com/watch?v=dEvnq6y5sIQ&w=640&h=360]
[youtube https://www.youtube.com/watch?v=mav4_JRdLh8&w=640&h=360]
[youtube https://www.youtube.com/watch?v=DjxjmXS3E5s&w=640&h=360]
[youtube https://www.youtube.com/watch?v=q9Qxve8MKKQ&w=640&h=360]
[youtube https://www.youtube.com/watch?v=dK_a_dCeOeU&w=640&h=360]