Lincoln was delighted to advocate the cases of those whom he knew to be wronged, but he would not defend the cause of the guilty.

If he discovered in the course of a trial that he was on the wrong side, he lost all interest, and ceased to make any exertion.

Once, while engaged in a prosecution, he discovered that his client's cause was not a good one, and he refused to make the plea. His associate, who was less scrupulous（小心谨慎的）, made the plea and obtained a decision in their favor. The fee was nine hundred dollars, half of which was tendered（偿付） to Mr. Lincoln, but he refused to accept a single cent of it.

His honesty was strongly illustrated by the way he kept his accounts with his law-partner. When he had taken a fee in the latter's absence, he put one half of it into his own pocket, and laid the other half carefully away, labeling it "Billy," the name by which he familiarly addressed his partner. When asked why be did not make a record of the amount and, for the time being, use the whole, Mr. Lincoln answered, "Because I promised my mother never to use money belonging to another person."

林肯非常乐意为那些他认为受到冤屈的人辩护，但是他却拒绝为那些确实有罪的人辩护。

如果在审判中发现自己的立场错误，就立刻都案件失去兴趣，不再辩护。

他参与了一起起诉案件。当他发现他的客户动机不良时，便拒绝为其申辩。他的一位做事不太谨慎的同事参与了辩护，并得到对他们有利的判决。辩护费为900美元，这位同事把其中的一半给了林肯，但是林肯一分钱也没拿。

林肯的诚实在下面的例子里得到最好的证明。他与他的伙伴记有详细的账目。但他的伙伴不在时，他仅拿走所得收入的一半，把另一半仔细地保存，写上同伴的名字：“贝利”。当被问到他这样做的原因，林肯回答道：“因为我曾经答应我的妈妈永远不拿属于别人的钱。”