Meanings of moral postulate in English

The existence of God is for him not merely a moral postulate, but a result of scientific reasoning.

From henceforth all the aspirations and achievements of the people were governed by a moral postulate, which was still unknown elsewhere in Europe.

Legislation, during the occultation of the great moral postulate Principle by the passage of Pecuniary Interest, is, at the best, but a melancholy affair.

I entertained doubts likewise, whether, in his own mind, he even laid all the stress, which he appears to do, on the moral postulates.