Providing you with an intellectual history of the 19th and 20th centuries is, I am afraid, beyond the scope of this discussion, for what I hope are obvious reasons. I must admit I rather assumed that anyone trying to pass themselves off as a conservative on this forum was at least vaguely familiar with this subject area.
Feel free to do a little homework. I guess you could just google around but you'd be better off engaging the subjects with a little more formal mode of inquiry.
Study the history of Marxism & Freudianism & Darwinism from the point of view of their rise and acceptance amongst the intellectual and academic elites in the West. This might not be a terrible place to start: http://www.firstthings.com/ftissues/ft9603/opinion/thistime.html