many rules which are quite sufficiently accounted for by their
manifest good sense, on the other, there are some which can only
be understood by reference to the infancy of procedure among the
German tribes, or to the social condition of Rome under the
Decemvirs.

I shall use the history of our law so far as it is necessary to
explain a conception or to interpret a rule, but no further. In
doing so there are two errors equally to be avoided both by
writer and reader. One is that of supposing, because an idea
seems very familiar and natural to us, that it has always been
so. Many things which we take for granted have had to be
laboriously fought out or thought out in past times. The other
mistake is the opposite one of asking too much of history. We
start with man full grown. It may be assumed that the earliest
barbarian whose practices are to be considered, had a good many
of the same feelings and passions as ourselves.

The first subject to be discussed is the general theory of
liability civil and criminal. The Common Law has changed a good
deal since the beginning of our series of reports, and the search
after a theory which may now be said to prevail is very much a
study of tendencies. I believe that it will be instructive to go
back to the early forms of liability, and to start from them.

It is commonly known that the early forms of legal procedure were
grounded in vengeance. Modern writers [3] have thought that the
Roman law started from the blood feud, and all the authorities
agree that the German law begun in that way. The feud led to the
composition, at first optional, then compulsory, by which the