What most attracted the founding father's to montesquieus explanation the separation of powers

Montesquieu saw man as exhibiting a general tendency towards evil, a tendency that manifests itself in selfishness, pride, envy, and the seeking after power. Man, though a reasoning animal, is led by his desires into immoderate acts. Montesquieu wrote that "A people like this, being always in ferment, are more easily conducted by their passions than by reason, which never produced any great effect in the mind of man." In the realm of politics this is of the greatest consequence: "Constant experience shows us that every man invested with power is apt to abuse it, and to carry his authority as far as it will go." However, this tendency towards the abuse of power can be moderated by the constitution of the government and by the laws, for, although by no means a starry-eyed utopian, Montesquieu, like the Greeks, believed that the nature of the State's constitution is of the greatest consequence. Thus Montesquieu commenced his work with a description of the three different types of government, their nature and their principles, for if he could establish these, then the laws would "flow thence as from their source."

Montesquieu style gave him an influence which a more precise and less interesting thinker would never have achieved, but more important than this is the fact that by changing the emphasis that English writers of the preceding half century had placed upon legislative supremacy and the mixed constitution, he paved the way for the doctrine of the separation of powers to emerge again as an autonomous theory of government. This theory was to develop in very different ways in Britain, in America, and on the continent of Europe, but from this time on, the doctrine of the separation of powers was no longer an English theory; it had become a universal criterion of a constitutional government.