Objection 1. It would seem that the damned do not blaspheme. Because some wicked men are deterred from blaspheming now, on account of the fear of future punishment. But the damned are undergoing these punishments, so that they abhor them yet more. Therefore, much more are they restrained from blaspheming.
Objection 2. Further, since blasphemy is a most grievous sin, it is most demeritorious. Now in the life to come there is no state of meriting or demeriting. Therefore there will be no place for blasphemy.
Objection 3. Further, it is written (Ecclesiastes 11:3) that "the tree... in what place soever it shall fall, there shall it be": whence it clearly follows that, after this life, man acquires neither merit nor sin, which he did not already possess in this life. Now many will be damned who were not blasphemous in this life. Neither, therefore, will they blaspheme in the life to come.
On the contrary, It is written (Apocalypse 16:9): "The men were scorched with great heat, and they blasphemed the name of God, Who hath power over these plagues," and a gloss on these words says that "those who are in hell, though aware that they are deservedly punished, will nevertheless complain that God is so powerful as to torture them thus." Now this would be blasphemy in their present state: and consequently it will also be in their future state.
I answer that, As stated above (A1,3), detestation of the Divine goodness is a necessary condition of blasphemy. Now those who are in hell retain their wicked will which is turned away from God's justice, since they love the things for which they are punished, would wish to use them if they could, and hate the punishments inflicted on them for those same sins. They regret indeed the sins which they have committed, not because they hate them, but because they are punished for them. Accordingly this detestation of the Divine justice is, in them, the interior blasphemy of the heart: and it is credible that after the resurrection they will blaspheme God with the tongue, even as the saints will praise Him with their voices.
Reply to Objection 1. In the present life men are deterred from blasphemy through fear of punishment which they think they can escape: whereas, in hell, the damned have no hope of escape, so that, in despair, they are borne towards whatever their wicked will suggests to them.
Reply to Objection 2. Merit and demerit belong to the state of a wayfarer, wherefore good is meritorious in them, while evil is demeritorious. On the blessed, on the other hand, good is not meritorious, but is part of their blissful reward, and, in like manner, in the damned, evil is not demeritorious, but is part of the punishment of damnation.
Reply to Objection 3. Whoever dies in mortal sin, bears with him a will that detests the Divine justice with regard to a certain thing, and in this respect there can be blasphemy in him.
Source: Summa Theologica (New Advent)