Sentence:  As such , one cannot fully understand the thought of the pre-Han and Han periods without knowing the meanings inherent in the Lo Shu ; but , conversely , one cannot <WSD>begin</WSD> to understand the Lo Shu without knowing something about the world view of the Old Chinese , which they felt they saw expressed in it . 
Meaning of the word marked with <WSD> tags:  take the first step or steps in carrying out an action