Complex sentence: This is the keynote of his famous work, "Geist des römischen Rechts auf den verschiedenen Stufen seiner Entwicklung" (1852--1865), which for originality of conception and lucidity of scientific reasoning placed its author in the forefront of modern Roman jurists.
Split into simpler sentences: This is the keynote of his famous work, "Geist des römischen Rechts auf den verschiedenen Stufen seiner Entwicklung" (1852--1865). Its originality and lucidity placed its author in the forefront of modern Roman jurists.