How does Rothbard build his apodictic certainty foundation?

He tells us exactly:

"My understanding of Ludwig von Mises' notion of the a priori... rests on Aristotle and St. Thomas."
— Murray Rothbard,

The synchronizing point around Aristotle & Aquinas' emphasis on the common good and human flourishing in community.

So what’s the problem? This is where I get stuck. To pull from St. Thomas, literally, is a declaration and definition of law requiring a legislator.

Aquinas’ Divine Reason is not the same as Rothbard’s Reason - there is a jump.

Is this where I am getting this wrong? Did Rothbard justify the de-theologizing (making it work without requiring belief in God as legislator) sufficiently?

St Thomas Summa Theologica I-II, Q. 90, Art. 4 ---> Law is an ordinance of reason for the common good, promulgated by one who cares for the community."

For Rothbard to cherry-pick the famous "Unjust laws are not laws" from the essence of St Thomas' grounding seems a point worth re-examining. The word cherry-picking " is used because I can not find anything in the original source material from Rothbard that describes the trade-off when you remove God.
Aquinas is grounded in “divine reason”, yet Rothbard reduces it to “reason.”

Rothbard gains something here, but what, exactly, does he lose? In crisis mode, Rothbard's call for decisive action appears reasonable, but at what cost? The main argument centers on what is sacrificed when urgent action is taken: does Rothbard's gain outweigh what may be lost? But in an era of prosperity?

The justification to remove “God” through a "modernization" for individual rights itself becomes problematic when the rational fabric of praxeology is to be independent of conditions, to avoid empirical subjectivism.

Is this not the exact point that Bitcoin thinking can strengthen this “Blindspot”?

Summa Theologica I-II, Q. 91, Art. 1–2 ---> Natural law as "participation in eternal law."

The obvious risk is that boundary-line that Jordan Peterson used to pound the table with - Who decides what is offensive"

IMHO, without God, the 'good' becomes subjective; the tyrant can claim his aggression as 'natural' if it serves his ends.