Sentence:  This trend has often been ascribed to the cult of the Five Elements itself , as though they had <WSD>served</WSD> as the base for all the rest ; but why did the Old Chinese postulate five elements , when the Ancient Near East - which may have initiated the idea that natural elements exerted influence in human life and activities - recognized only four ? 
Meaning of the word marked with <WSD> tags:  serve a purpose, role, or function