ts, has been occasioned by the error of
ascribing to the mental condition of an unformed society a faculty
which pre-eminently belongs to an advanced stage of intellectual
development, the faculty of distinguishing in speculation ideas which
are blended in practice. We have indications not to be mistaken of a
state of social affairs in which Conveyances and Contracts were
practically confounded; nor did the discrepance of the conceptions
become perceptible till men had begun to adopt a distinct practice in
contracting and conveying.

It may here be observed that we know enough of ancient Roman law to
give some idea of the mode of transformation followed by legal
conceptions and by legal phraseology in the infancy of Jurisprudence.
The change which they undergo appears to be a change from general to
special; or, as we might otherwise express it, the ancient conceptions
and the ancient terms are subjected to a process of gradual
specialisation. An ancient legal conception corresponds not to one but
to several modern conceptions. An ancient technical expression serves
to indicate a variety of things which in modern law have separate
names allotted to them. If however we take up the history of
Jurisprudence at the next stage, we find that the subordinate
conceptions have gradually disengaged themselves and that the old
general names are giving way to special appellations. The old general
conception is not obliterated, but it has ceased to cover more than
one or a few of the notions which it first included. So too the old
technical name remains, but it discharges only one of the functions
which it once performed. We may exemplify this phenomenon in various
ways. Patriarchal Power of all sorts appears, for instance, to have
been once conceived as identical in character, and it was doubtless
distinguished by one name. The Power exercised by the ancestor was the
same whether it was exercised over the family or the material
property--over flocks, herds, slaves, children, or wife. We cannot be
absolutely certain of its old Roman name, but there is very strong
reason for believing, from the number of expressions indicating shades
of the notion of _power_ into which the word _manus_ enters, that the
ancient general term was _manus_. But, when Roman law has advanced a
little, both the name and the idea have become specialised. Power is
discriminated, both in word and in conception, according to the
object over which it is exerted.