Without the fuller context, it will be hard to know what is exactly being stated. However, the word here suggest a few points.
First, there is an exhortation to follow nature. This is explained further by stating that the reader should change his or her mentality to match that of nature. In other words, the reader should strive to think nature's thoughts after it.
Second, nature is praised as consistent and more importantly unerring. Along with these two qualities of nature, there is a praise of nature. It is divinely bright, clear, and beautiful.
Third, reasons are given as to why the reader should follow nature. It is a the source of many things. It is also the standard for beauty. Finally, it is humble, that is, without show and without pomp.