This is from Divine Providence, n. 136:2 (emphasis added):
The external cannot compel the internal, but the internal can compel the external. Who can be compelled to believe and to love? One can no more be compelled to believe than to think that a thing is so when he thinks that it is not so; and one can no more be compelled to love than to will what he does not will, for belief belongs to the thought and love to the will. There is, however, an internal which may be restrained by the external from speaking ill against the laws of the kingdom, the moralities of life and the sanctities of the Church. To this extent the internal may be compelled by threats and punishments; and it, moreover, is compelled and ought to be. This internal, however, is not the human internal that is properly so-called: it is an internal that man has in common with beasts; and beasts can be compelled. The human internal has its seat above this animal internal; and it is the human internal that is here meant, and it cannot be compelled.
So, should we have laws against speaking against the U.S. law, morality, and religion? I’m not sure – I’m just putting this out there to hear what other people have to say.
An interesting question. I don’t have a full answer for you, but I will suggest that overall I get the sense that the heavenly doctrines are pro-free-speech. For instance:
Reading the entirety of the number you quote, past the portion you’ve highlighted in bold, I get the sense that what is being spoken of is more of an animalistic, gut-level, unthinking blaspheming, which is distinct from a reasoned argument against the divine. Perhaps what DP is saying, here, is that rudeness ought to be restrained, but not dissent.
Keep in mind, also, that law is not the only form of compulsion. These days we are too quick to jump to civil government for all of our solutions. Shunning, for instance, is another form of compulsion. Likewise, so is the rule of parents or teachers over children by means of rules. Also, corporate policies regarding public behavior as incorporated into employment agreements. There are lots of ways of compelling that require no action of legislature at all.
Just some thoughts.