 Let us now pause for a moment and reflect on the way the philosophical spirit developed in Chosŏn Korea; the Chosŏn thought started with a strong Principle-Vital Force dualism but, as it progressed further, many ended up embracing a Vital Force-inclined view. For example, Sŏ Kyŏngdok (1489–1546: pen name: Hwadam) was the first major philosopher who advocated the philosophy based on Vital Force.