hough it is likely that the qualification,
_Juris Gentium_, stamps the recency of their origin, yet this very
expression, which attributes them to the "Law of Nations," has in
modern times produced the notion of their extreme antiquity. For,
when the "Law of Nations" had been converted into the "Law of Nature,"
it seemed to be implied that the Consensual Contracts were the type of
the agreements most congenial to the natural state; and hence arose
the singular belief that the younger the civilisation, the simpler
must be its forms of contract.

The Consensual Contracts, it will be observed, were extremely limited
in number. But it cannot be doubted that they constituted the stage in
the history of Contract-law from which all modern conceptions of
contract took their start. The motion of the will which constitutes
agreement was now completely insulated, and became the subject of
separate contemplation; forms were entirely eliminated from the notion
of contract, and external acts were only regarded as symbols of the
internal act of volition. The Consensual Contracts had, moreover, been
classed in the Jus Gentium, and it was not long before this
classification drew with it the inference that they were the species
of agreement which represented the engagements approved of by Nature
and included in her code. This point once reached, we are prepared for
several celebrated doctrines and distinctions of the Roman lawyers.
One of them is the distinction between Natural and Civil Obligations.
When a person of full intellectual maturity had deliberately bound
himself by an engagement, he was said to be under a _natural
obligation_, even though he had omitted some necessary formality, and
even though through some technical impediment he was devoid of the
formal capacity for making a valid contract. The law (and this is what
the distinction implies) would not enforce the obligation, but it did
not absolutely refuse to recognise it; and _natural obligations_
differed in many respects from obligations which were merely null and
void, more particularly in the circumstance that they could be civilly
confirmed, if the capacity for contract were subsequently acquired.
Another very peculiar doctrine of the jurisconsults could not have had
its origin earlier than the period at which the Convention was severed
from the technical ingredients of Contract. They taught that though
nothing but a Contract could be the foundation of an _action_, a