Complex sentence: Although controversial at its time though today considered mostly normative, the 13 principles laid out by the 12th century Spanish Jewish philosopher Maimonides are formalized in the prayerbook following daily morning services.
Split into simpler sentences: Although controversial at its time, the 13 principles laid out by the 12th century Spanish Jewish philosopher Maimonides are now considered mostly normative. They are formalized in the prayerbook following daily morning services.