d
that the Paterfamilias was answerable for the delicts (or _torts_) of
his Sons under Power. He was similarly liable for the torts of his
slaves; but in both cases he originally possessed the singular
privilege of tendering the delinquent's person in full satisfaction of
the damage. The responsibility thus incurred on behalf of sons,
coupled with the mutual incapacity of parent and Child under Power to
sue one another, has seemed to some jurists to be best explained by
the assumption of a "unity of person" between the Paterfamilias and
the Filius-familias. In the chapter on Successions I shall attempt
to show in what sense, and to what extent, this "unity" can be
accepted as a reality. I can only say at present that these
responsibilities of the Paterfamilias, and other legal phenomena which
will be discussed hereafter, appear to me to point at certain _duties_
of the primitive Patriarchal chieftain which balanced his _rights_. I
conceive that, if he disposed absolutely of the persons and fortune of
his clansmen, this representative ownership was coextensive with a
liability to provide for all members of the brotherhood out of the
common fund. The difficulty is to throw ourselves out of our habitual
associations sufficiently for conceiving the nature of his obligation.
It was not a legal duty, for law had not yet penetrated into the
precinct of the Family. To call it _moral_ is perhaps to anticipate
the ideas belonging to a later stage of mental development; but the
expression "moral obligation" is significant enough for our purpose,
if we understand by it a duty semi-consciously followed and enforced
rather by instinct and habit than by definite sanctions.

The Patria Potestas, in its normal shape, has not been, and, as it
seems to me, could not have been, a generally durable institution. The
proof of its former universality is therefore incomplete so long as we
consider it by itself; but the demonstration may be carried much
further by examining other departments of ancient law which depend on
it ultimately, but not by a thread of connection visible in all its
parts or to all eyes. Let us turn for example to Kinship, or in other
words, to the scale on which the proximity of relatives to each other
is calculated in archaic jurisprudence. Here again it will be
convenient to employ the Roman terms, Agnatic and Cognatic
relationship. _Cognatic_ relationship is simply the conception of
kinship familiar to modern ideas; i