"It was the general opinion of ancient nations, that the divi..." — John Adams quote meaning

It was the general opinion of ancient nations, that the divinity alone was adequate to the important office of giving laws to men... and modern nations, in the consecrations of kings, and in several superstitious chimeras of divine rights in princes and nobles, are nearly unanimous in preserving remnants of it... Is the jealousy of power, and the envy of superiority, so strong in all men, that no considerations of public or private utility are sufficient to engage their submission to rules for their own happiness? Or is the disposition to imposture so prevalent in men of experience, that their private views of ambition and avarice can be accomplished only by artifice? — … There is nothing in which mankind have been more unanimous; yet nothing can be inferred from it more than this, that the multitude have always been credulous, and the few artful. The United States of America have exhibited, perhaps, the first example of governments erected on the simple principles of nature: and if men are now sufficiently enlightened to disabuse themselves of artifice, imposture, hypocrisy, and superstition, they will consider this event as an era in their history. Although the detail of the formation of the American governments is at present little known or regarded either in Europe or America, it may hereafter become an object of curiosity. It will never be pretended that any persons employed in that service had any interviews with the gods, or were in any degree under the inspiration of heaven, any more than those at work upon ships or houses, or labouring in merchandize or agriculture: it will for ever be acknowledged that these governments were contrived merely by the use of reason and the senses. As Copley painted Chatham, West, Wolf, and Trumbull, Warren and Montgomery; as Dwight, Barlow, Trumbull, and Humphries composed their verse, and Belknap and Ramzay history; as Godfrey invented his quadrant, and Rittenhouse his planetarium; as Boylston practised inoculation, and