This was a piece of contrasted psychology in which the genius of Browning revelled, and he followed all the windings of it in both these hearts with the zest of an explorer.
They were labyrinthine, but the more labyrinthine the better he was pleased.

Guido's first speech is made before the court in his defence.
We see disclosed the outer skin of the man's soul, all that he would have the world know of him--cynical, mocking, not cruel, not affectionate, a man of the world whom life had disappointed, and who wishing to establish himself in a retired life by marriage had been deceived and betrayed, he pleads, by his wife and her parents--an injured soul who, stung at last into fury at having a son foisted on him, vindicates his honour.

And in this vindication his hypocrisy slips at intervals from him, because his hatred of his wife is too much for his hypocrisy.
This is the only touch of the wolf in the man--his cruel teeth shown momentarily through the smooth surface of his defence.

A weaker poet would have left him there, not having capacity for more.

But Browning, so rich in thought he was, had only begun to draw him.