Original: Rather than focusing on the I Ching like other Neo-Confucians, he chose to emphasize the Four Books: the Great Learning, the Doctrine of the Mean, the Analects of Confucius, and the Mencius as the core curriculum for aspiring scholar officials.
Simplified: Rather than focusing on the Book of Changes like other Neo-Confucians, he chose to emphasize the Four Books: the Great Learning, the Doctrine of the Mean, the Analects of Confucius, and the Mencius as the core curriculum (thing to learn) for aspiring scholar officials.