tán / ào / de / zhé / lǐ / xū / yào / fǎn / fù / sī / kǎo / bù / néng / zhǐ / kàn / yí / biàn / jiù / xià / jié / lùn

潭奥的哲理需要反复思考，不能只看一遍就下结论。

Profound ideas require repeated reflection; you cannot draw a conclusion after reading them only once.