In his book America's God and Country (p. 453), William Federer claims that Montesquieu based his theory of divided powers on two Biblical passages: Isaiah 33:22, and Jeremiah 17:19. The Isaiah passage reads as follows:
The problem with Federer's argument is that it is not true. Montesquieu develops his argument for separation of powers in Book XI of The Spirit of the Laws, and nowhere in this book does he reference Isaiah, Jeremiah, or any other book of the Bible. On the contrary, Montesquieu's examples in this section are all drawn from contemporary European and pre-Christian Roman and Germanic history. Nor can we find references to Isaiah and Jeremiah elsewhere in the book. While Montesquieu does occasionally reference the Bible in The Spirit of the Laws, these references are mostly to the Pentateuch, and are never to the prophetic books of the Old Testament.
It is difficult to argue that Montesquieu based his theory of divided powers on Isaiah and Jeremiah when he doesn't quote from these books, and when he bases his examples on other sources. We conclude that Federer has either misunderstood Montesquieu, is simply repeating someone else's inaccurate argument, or is intentionally misleading his readers.
But what of Federer's reference to page 457 of Cohler's translation of The Spirit of the Laws? We've located a copy of this work, and this page turns out to be nothing more than the title page for the fifth section of Cohler's translation; it has no text except the words "Part 5." We will charitably assume that the reference is a misprint, but sloppy editing on Federer's part does little to convince us that he knows what he's talking about with respect to Montesquieu. Additionally, Cohler's work contains an detailed appendix in which she indexes all the sources Montesquieu used in writing The Spirit of the Laws, and while we find several references to various books of the Bible, there are no references to Isaiah and Jeremiah. Far from proving his argument, Cohler's translation is further proof that Federer's claim is incorrect..
For what it's worth, we don't think Federer is the originator of the
myth that Montesquieu derived his theory from the Bible. Barton's The
Myth of Separation predates Federer, and Barton makes essentially the
same argument (albeit without footnotes). The idea was probably circulating
long before either Federer or Barton wrote their books. But it makes no
difference. It is a myth. There is absolutely no reason to believe that
Montesquieu derived his ideas from the Bible. The myth should be put to
rest before it does any more disservice.