>>24520973 (OP)Hegel, like that other anon said. A lot of his writing are a response to him. Hegel was a very popular philosopher back at his time. There are lots of decent commentaries on him, get those "companion to Kierkegaard" from some whatever publisher, you can easily download those. I think that I got that Blackwell one that was ok (as in me, a layperson that has read some history of philosophy books, being able to understand what they were writing about), but there are lots of different ones.