The authoritative presence of the past in traditions is frequently
unnoticed by participants. Indeed, the past is often most power-
fully and pervasively present when it is not known to be past or
present. It is simply 'obvious' or 'natural',an unremarkedpiece of the furniture of the world. This is true of many moral, religious
and political beliefs, ideologies, legal traditions, scientific proce- dures, and the vast cultural inheritances they embody. On the
other hand, the pastness of elements of one's present can be
recognised and appropriated in a specifically traditional way, when what.is known or thought to be the past of one's race,
vocation, institution etc., is considered to be of continuing signifi- cance.
In law the past has profound present significance in both these senses. Simple reflection on what is involved in knowing the law of
a single jurisdiction suggests the importance of the unnoticed pres- ent-past in law. For as everyone knows but jurists sometimes forget, 'to know a legal system is not just to have learned its rules but to understand how the rules are put together, how the system is structured, how the rules are interpreted'.11 Such understanding is important not merely, or even especially, for the historian or theorist of law who seeks to account for these things. It is in
fact an unsung precondition of practical lawyering; the 'tacit' knowledge12 which underlies competence within any legal or indeed any social practice. Mastery of such underlying knowl-