Like Beasts of the Field or Forest

On July 5, 1814, Thomas Jefferson wrote a letter to John Adams, including

Having more leisure there than here for my reading, I amused myself with reading seriously Plato's republic. I am wrong however in calling it amusement, for it was the heaviest task-work I ever went through. I had occasionally before taken up some of his other works, but scarcely ever had patience to go through a whole dialogue. While wading thro' the whimsies, the puerilities, and unintelligible jargon of this work, I laid it down often to ask myself how it could have been that the world should have so long consented to give reputation to such nonsense as this? How the soi-disant Christian world indeed should have done it is a piece of historical curiosity. But  how could the Roman good sense do it? And particularly how could Cicero bestow such eulogies on Plato? Altho' Cicero did not wield the dense logic of Demosthenes, yet he was able, learned, laborious, practised in the world, and honest...
  It is fortunate for us that Platonic republicanism has not obtained the same favor as Platonic Christianity; or we should now have been all living, men, women and children, pell mell together, like beasts of the field or forest.

 Adams's reply, on July 16, was no more favorable:

I am very glad you have seriously read Plato: and still more rejoiced to find that your reflections upon him so perfectly harmonize with mine. Some thirty Years ago I took upon me the severe task of going through all his works. With the help of two Latin translations, and one English and one French Translation and comparing some of the most remarkable passages with the Greek, I laboured through the tedious toil. My disappointment was very great, my Astonishment was greater, and my disgust was shocking. Two Things only did I learn from him, 1. that Franklins Ideas of exempting Husbandmen and Mariners etc. from the depredations of War were borrowed from him. 2. That Sneezing is a cure for the Hickups. Accordingly I have cured myself and all my Friends of that provoking disorder, for thirty Years with a Pinch of Snuff.
  Some Parts of some of his Dialogues are entertaining, like the Writings of Rousseau: but his Laws and his Republick from which I expected most, disappointed me most. I could scarcely exclude the suspicion that he intended the latter  as a bitter Satyre upon all Republican Government, as Xenophon undoubtedly designed by his Essay on Democracy, to ridicule that species of Republick.

Being and Logos: The Way of Platonic Dialogue by John Sallis considers The Republic among other dialogues. In the course of reading it, I have re-read or read the dialogues considered, most recently The Republic. I can see how little it would have appealed to men of the Enlightenment. Of course Sallis belongs to a school that considers that Plato was playing a much deeper, often comic game in his dialogues. But I don't suppose that either Jefferson or Adams would have cared for a sentence such as

This circumstance is of utmost importance for understanding properly what is said in The Republic about dialectic; it is especially important as a warning against making too much of this discussion, and on the other hand, against taking it too seriously.