for such
conventions among men as they should adjudge best for their own
utility and happiness. The most vigorous champion of this latter
theory appears to have been one Carneades, a Greek philosopher of the
second century B.C., said to have been the founder of the third
Academy and expounder of the philosophy of probabilities and to have
possessed the acutest mind of antiquity. In a course of lectures at
Rome he stated the arguments for the orthodox view of justice and
then boldly assumed to answer them and demonstrate that justice was
not a virtue at all as virtue was defined by the philosophers, but was
merely a convention; was what men should agree to be a sound basis for
the maintenance of civil society, and hence that it varied with times,
places, circumstances, and even opinions. This argument evidently had
much effect upon public opinion, for Cato urged in the Senate that
Carneades be banished because dangerous to the state.

So great was the influence of Carneades that a century later Cicero, a
disciple of the Stoic school of philosophy, thought it necessary to
refute him specifically as the chief heretic, and to uphold the
orthodox theory against his arguments. Cicero denounced with eloquent
warmth the doctrine that utility was the foundation of justice. He
declared that, not utility, but nature, was the source of justice,
that justice was a principle of nature, the ultimate principle behind
all law. To abridge the familiar quotation from his "De Republica,"
"There is a law which is the same as true reason, accordant with
nature, a law which is constant and eternal, which calls and commands
to duty, which warns and terrifies men from the practice of deceit.
This law is not one thing at Rome, another at Athens, but is eternal
and immutable, the expression and command of Deity." In his treatise
"De Legibus" he declared that men are born to justice; that right is
established not by opinion but by nature; that all civil law is but
the expression or application of this eternal law of nature; that the
people or the prince may make laws but these have not the true
character of law unless they be derived from the ultimate law; that
the source and foundation of right law must be looked for in that
supreme law which came into being ages before any state was formed.

This theory of the Stoics so eloquently urged by Cicero was
practically the _jus naturale_ of the Roman jurists of classical
times, though more moderatel