Give examples of how Alec is honest with himself on what kind of person he is (bad) and examples of how Angel is dishonest with what kind of person he is (likes to think he's better than society but really is just like anybody else).

After Alec "seduces," in other words, rapes and impregnates Tess, she accuses him of taking advantage of her. He agrees, saying:

‘I did wrong—I admit it.’ He dropped into some little bitterness as he continued: ‘Only you needn’t be so everlastingly flinging it in my face. I am ready to pay to the uttermost farthing. You know you need not work in the fields or the dairies again.

Tess decides, after they are married, to confess to Angel what happened with Alec, interestingly using exactly the same term ("uttermost farthing") as Alec. She thinks to herself:

She would pay to the uttermost farthing; she would tell, there and then.

But first Angel confesses to her that he once spent two days in "dissipation" (having sex) with a stranger. However, when Tess confesses to what happened with Alec, Angel shows he is unable to rise above the conventional thinking of his society, which will condemn the woman for doing just what the man did. Tess says to Angel, realizing he is shocked:

Forgive me as you are forgiven! I forgive YOU, Angel.

But Angel shows himself to be a hypocrite who judges Tess by a harsher standard than she has judged him, even though she was completely innocent when Alec raped her. Angel says to her:

O Tess, forgiveness does not apply to the case! You were one person; now you are another.

Angel, in his inability to forgive others as he has been forgiven, shows he is not as pure and moral as he would like to believe. He is dishonest with himself in a way that Alec is not. If he were honest with himself, he would admit he is no purer than Tess.