I think this is probably one of the very few decent books in the "radical thinkers" series, no only is it readable in a very nice plain prose but it succeeds in communicating very nicely the major developments in liberalism, democracy and socialism from their inceptions to the present day, it does so with some style in a series of short, succinct chapters.
The concepts of and emergence of individual rights, individual freedom and individual proprietorship, then with democratisation the concepts of an emergence of social rights, social freedoms and criticisms of individual proprietorship, central to socialism's emergence, are dealt with.
The final conclusion is that there are two seperate and competiting definitions of liberty, positive and negative, freedom to and freedom from, Bobbio believes that with the retreat to first principles of individual proprietorship and market forces of capitalist/liberal intellectuals like Nozick are returning to an authentic liberalism which of necessity opposes and exists independently and apart from conceptual or practical democracy.
I cant level many criticisms at this book, the writing is superb and the content manages to summarise a lot of political history without polemic or bias, on the other hand if anyone is seeking to examine the concept of negative liberty and its application to a real world of individuals vulnerable to structural unemployment or predatory behaviour, ie were the same negative liberties could be threatened by firms other than government operating within the legal parameters established by government, this is only a start.