how did the author begin his topic?

I'm not sure which topic you are referring to. THere are quite a few. The introduction states that, "Thought grows out of environment". He then goes on to discuss the various interpretations of Confucius over the centuries.

Aslan is correct, you haven't referred to any specific topic in your question. From a completely different perspective could you possibly mean how Confucius introduces his precepts?

Throughout, Confucius refers to "The Master said," the master of course was Confucius......... but you have to remember that this work was compiled over centuries by many different men, and that there are times when we seem to have a slightly different outlook runnibg throught it. But all in all, each topic is begun in the same way.