How you cite it depends on the citation format for the paper as a whole, but most major formats now have instructions on how to cite blogs. So check the reference book/website for whatever formatting school section about how to cite blogs. A decent example is the owl's guide to citing "electronic resources" in MLA which is a fairly common style for philosophy papers.
Edit-fixed typo
If it's worth saying, but not worth its own post, even in Discussion, it goes here.