I guess my critique won't be so much on the content as on the writing itself (a horrible [and yet useful] habit I have developed in my first year of college as an English major). I think that the article could afford to expand with more detail even on simple terms. While "hero" and "anti-hero" may seem rather self-explanatory, a formal definition would make the article more complete and applicable. Also, I believe that more could be written regarding how characters can or should go about resolving such moral dilemmas, what makes the heroic character heroic in such trials, and why he or she can still be heroic even if he or she fails or falters in such a decision.
As a whole, I like the direction but feel that it does not go far enough in-depth to properly explore the many facets and distinctions between the two character archetypes that are proposed.
Also, I think that it would be useful to explain why it is that the author only believes there are those four archetypes (that is, how they are all-encompassing and how any character can be classified under those categories; by extension, this requires these categories to be defined clearly as I suggested before).
I'm reminded of the comments my Senior English teacher often wrote on my papers: "So what?, "Why is this important?," "Explain," "Elaborate," and when I finally made the corrections to my writing in future essays, these became, "Yes!" I would like to be able to exclaim, "Yes!" about this article, and it is intriguing, but it isn't astounding. At the same time, I don't think it should be the length of a research paper (20-25 pages), even if it already feels like it has that tone (which I have actually come to enjoy).