legislations advocates were compelled to swear that they would not
defend causes which they thought or discovered to be unjust.[35] St.
Thomas Aquinas has laid down in emphatic terms that any lawyer who
undertakes the defence of an unjust cause is committing a grievous sin.
It is unlawful, he contends, to co-operate with any one who is doing
wrong, and an advocate clearly counsels and assists him whose cause he
undertakes. Modern Catholic casuists have dealt with the subject in the
same spirit. They admit, indeed, that an advocate may undertake the
defence of a criminal whom he knows to be guilty, in order to bring to
light all extenuating circumstances, but they contend that no advocate
should undertake a civil cause unless by a previous and careful
examination he has convinced himself that it is a just one; that no
advocate can without sin undertake a cause which he knows or strongly
believes to be unjust; that if he has done so he is himself bound in
conscience to make restitution to the party that has been injured by his
advocacy; that if in the course of a trial he discovers that a cause
which he had believed to be just is unjust he must try to persuade his
client to desist, and if he fails in this must himself abandon the
cause, though without informing the opposite party of the conclusion at
which he had arrived; that in conducting his case he must abstain from
wounding the reputation of his neighbour or endeavouring to influence
the judges by bringing before them misdeeds of his opponent which are
not connected with and are not essential to the case.[36] As lately as
1886 an order was issued from Rome, with the express approbation of the
Pope, forbidding any Catholic, mayor or judge, to take part in a
divorce case, as divorce is absolutely condemned by the Church.[37]

There have been, and perhaps still are, instances of lawyers
endeavouring to limit their practice to cases which they believed to be
just. Sir Matthew Hale is a conspicuous example, but he acknowledged
that he considerably relaxed his rule on the subject, having found in
two instances that cases which at the first blush seemed very worthless
were in truth well founded. As a general rule English lawyers make no
discrimination on this ground in accepting briefs unless the injustice
is very flagrant, nor will they, except in very extreme cases, do their
client the great injury of throwing up a brief which they have once
accepted. They contend that by