Recently I have taken it upon myself to gain a basic understanding of philosophy and linear algebra. I found this primer book (http://www.qcc.cuny.edu/SocialSciences/ppecorino/INTRO_TEXT/...) and I try to read it when I have some free time.
For linear algebra, I have been watching this MIT OpenCourseWare lecture series taught by Gilbert Strang: https://ocw.mit.edu/courses/mathematics/18-06sc-linear-algeb...
MITOCW is a great place for anyone looking to expand on their current knowledge base and an alternative for those seeking to take a course that they did not have the opportunity to take in college.