I have always been interested in the theoretical side of history and this remains one of the best books to start with. It has been a few years since I was at University, but this used to be a set text for first year undergraduates, in order to give them some understanding of the 'history of history'. Carr's text is highly readable and his analogies very useful - ie. thinking of historians as merely individuals in a very long, winding procession of people through a mountainous valley - looking back at events going on further back in the queue, their views differing according to whereabouts in the procession he or she was at the time. Still a great starting point for an often complex subject.