While it is no doubt possible to subsume many kinds of inquiry under the head of historical jurisprudence one should certainly distinguish between two rather different kinds. First there is the kind that takes a particular legal notion or idea as it becomes crystallised at some point in a country’s legal history and traces its subsequent history in legal thought, investigating its diffusion and influence and assessing its continuing utility. Such an inquiry is concerned only with the facts in the sense of the ascertainment of what has actually happened. It is in no degree speculative; nor does it seek to investigate the relationship between social conditions and legal notions or rely upon any particular theory of social evolution.