In the < Tao Te Ching > , it said,
" Tao gives birth to one, one produces two, two produces three, three then produces everything on earth (or in universe). Everything is having yin at its back with yang in front, both qi by nature against each other but seem co-existence in harmony. What human dislike is, living on alone and lonely since born to dead, also with no achievement in life. However, such bad things are usually what the emperior, rulers often used to describe themselve. As such, things seem to lose but gains ; things seem to gain but lose. ". 道德經:道生一，一生二，二生三，三生萬物。萬物負陰而抱陽，沖氣以為和。人之所惡，唯孤、寡、不穀，而王公以為稱。故物或損之而益，或益之而損。
The above " one produce two, two produces three, three produces everything", is a very popular phrase being quoted in several ancient chinese classical feng shui literatures, for the foundation of cosmology as per the ancient chinese science anc philosophy views.
My interpretation is,
" Tao gives birth to one " Tao begins with nothing as empty. When too long being nothing and empty would gradually be into incubation of something (named it, one). Then, one (tai-chi, with yin and yang in one body) is born.
"One produces two" Being one body with both yin and yang qi but having conflicts inside too long, it splits into two (yin separate with yang into two separate zi sets) . This has created the pure yang, namely Qian qi , and pure yin, namely Kun qi.
"Two produces three" Once yin is separate with yang, both were into attracting each other so these two into incubation by themselve into "new next generation", called "three". So, Qian produced Dui, Li, Zhen, whereas Kun produces Gen, Kan, Xun. By then, the 8 trigrams qi existed.
"Three produces everything" With the 8 separate trigrams of qi, they continued to produce "new next generations" multiplied via the same mechanism, then the 64 trigrams were created, then into next new... for everything on earth, in universe...
"Everything has yin at its back and yang in front" No matter how many multifications of production into new generations transformed into everything on earth, in universe, all are still carrying the same DNA of yin and yang elements inside as well as their characteristic.
My view above is in fact in line with what the famous master Shao Yang in ancient china song dynasty saying " one changes then creates two, two changes then creates four, three changes then creates 8 trigrams" 邵雍曰：“一变而二，二变而四，三变而八卦成矣。
In ancient chinese feng shui science, there is an old jargon phrase " all and every single object (includes creature, plants, stones, water,air, building.....) has its own tai-chi inside.
This means, everything has its own yin yang 5 elements qi inside however may vary from others due to size, form, shape, location, position, active or inactive...etc..
All these then into the scope of feng shui science, dealing with the qi impact, eg. between human and mansion, mansion with the construction materals, mansion with its surrounding objects (enviroment), geographical location with weather, natural resouces, etc.....
Not limited to these above, it would mean the impacts to individual human with other human and creature for relationships which would lead to success, failure, harmony, violent, love, hate, healthy, sickness......which named "destiny", in chinese astrology, eg. Bazi, zi-wei dou shu,... , methodolgy created to base on the same DNA conception for destiny reading and forcasts.
