Sansai [三才]
The characters/ideograms mean "three powers; heaven, earth and man." The first character means, "three," the second character means, "genius; years old; cubic shaku."
Sansai refers to the three powers represented within the ancient classic, "I Ching." In the hakke or eight trigrams the three lines generally refer to the three powers. There are several combinations up to the hexagrams used in the I Ching that hold the positions of heaven, earth and man. Some understand this to mean heaven-man-earth where man standing on the earth is open to the influences of the heavens and earth. This is maybe the simplest theory of the three powers.
In Isshinryu Tatsuo-san believed wholeheartedly in the three powers. He used such classic beliefs along with some ancient classics such as the I Ching for his work in divination or fortune telling. At the entrance to one of his dojo you will see characters referencing this belief and work to include his birth hexagram.
Since the hexagrams, 64, are derived from combinations of the eight trigrams, hakke, you will immediately notice their influence toward the new system of Isshinryu by the eight empty hand kata. It also becomes apparent when you receive the original "eight" ken-po goku-i along with the silk promotion certificates (i.e. these were presented to many of the first American practitioners in the late fifties and early sixties, etc.).
A.J. Advincula sensei often speaks of the three powers within Isshinryu, i.e. Naihanchi-n-Sanchin, Chinkuchi, and muchimi-n-gamaku. This seems to be the core or essence of the make up of Isshinryu.
There are many other symbolic representations toward the three powers through out the Isshinryu system as created and named by Tatsuo-san. Take a look at the Isshinryu-no-megami, etc.
Hakke [八卦]
The characters/ideograms mean "eight trigrams; divination signs." The first character means, "eight," the second character means, "a divination sign."
The eight trigrams are a product of the one. The one being the great tai chi that at the birth of the Universe separated into the two, the in-n-yo or yin-n-yang. The yin and yang were represented by a single solid line and single broken line. The two lines are then combined into pairs making four pairs called young yin, young yang, old yin and old yang, etc.
These four have a third line to represent the three powers creating eight trigrams or hakke, the divination signs used to create the sixty-four hexagrams used in the ancient classic, the I Ching.
The eight kata of Isshinryu as created through divination processes over many years of practice by Tatsuo-san are given birth from the one, Tatsuo-san, through the marriage of the two, Naihanchi from Shorinryu and Sanchin from Gojuryu, giving birth to the one, Isshinryu or the one heart way. Within Isshinryu the essence that is fundamental principle of the system are chinkuchi, muchimi and gamaku, i.e. whereby the true power of the system manifest.
In all things there is one and in Isshinryu, born from the one to the many as manifested by the three powers within Isshinryu, i.e. the father and mother paired to give birth to the one where the three powers combine and are named, Isshinryu. A manifestation of the two forces, yin and yang or naihanchi and sanchin or shorin and goju - soft-hard/yin-yan/in-yo.
Inyo [陰陽] ☯
The characters/ideograms mean "cosmic dual forces; yin and yang; sun and moon, etc." The first character means, "shade; yin; negative; secret; shadow," the second character means, "sunshine; yang principle; positive; male; heaven; daytime."
