Countering with two Catholic moral | ethical philosophers doesn't negate the suggestion of Cicero, it seems to be just an attempt to make the first proposition a second time.
That's just my drive by two cents worth, FWiW.
It's going to take more time commitment than people reading random forum posts will give to do that. It would be better to try summarising some aspect of his ideas (which is of course a task that would demand time from whoever wishes to promote him). That's why I said the comment isn't helpful.
Would you be willing to give the hours+ time commitment if a random stranger said the two words "Read [name]" with no further elaboration or would you ignore it? It would be more helpful in a discussion to bring actual ideas to the table, or else the discussion would consist of no more than reading recommendations.
In a thread about education, I expect the responses of the educated.
When an absolute position is taken a single exception rebuts the absolute.
If a comment is made regarding the absolute necessity of religion as grounding for morals and virtue and a simple response is given "Read X" then I expect that X addresses either supoort or raises an exception.
Cicero is sufficiently well known for many to be aware of the material, those that are unaware (in a thread about education) should be curious enough to learn more and advance their own position as to why Cicero may or may not be a suitable rebuttal.
FWiW I felt the comment given re: Cicero to be neccesary and sufficient and I'd tip my hat to the user if I had a hat, were to cross paths, and recognised them as such.
But this is just me, a random drive by HN commenter.
Each to their own.
I, for one, made no such comment.
I've been attempting to express the moral argument for God. Religion doesn't feature, as such.
(I'm trying to point out that your comment isn't helpful to the discussion.)