Complex sentence: He was attracted by the movement's dedication to the Enlightenment principles of rationality, reason and fraternalism; the American lodges did not share the anti-clerical perspective that made the European lodges so controversial.
Split into simpler sentences: He was attracted by the movement's dedication to the Enlightenment principles of rationality, reason, and fraternalism. The American lodges did not share the anti-clerical perspective that made the European lodges so controversial.