Name History
The history of Sephiroth's name, derived from Sefirot.
The Sefirot
Sephiroth's name is derived from the Jewish concept of 'Sefirot' ("Tree of Life"), which is part of a mystical Jewish doctrine that is called the 'Kabbalah', or 'Tradition'. It talks of ten creative forces/spiritual worlds that intermingle between the world that we live in, and with God. God is infinite and therefore cannot be fully comprehended by the human mind, therefore this Kabbalah helps believers
The Tree of Life originated from Babylonia, where it is believed that only the gods may take its fruit, and any mortal who attempted to do so will be punished. This can also be alluded to the Tree of Life whose fruit Adam and Eve took in the Bible. The Ten Sefirot were constructed in such a way as the upper sefirot has all the properties and powers of the one below it. They are as follows:
Ein Sof - The Infinite; the true hidden essence of God unknown to humans.Keter - Divine Crown; "pillars of light", this is the aspect of God that can be understood by humans.
Hochmah - Divine Crown; the contemplative aspects of God's Thought,a point where reality that humans can understand emanates from.
Binah - Understanding; a feminine element called the mother of the Shekhinah (see below) referring to the analytical aspect of God's thought.
Hesed - Merct or Love; benevolent and masculine side of God.
Geburah / Din - Justice; divine punishment and wrath that controls the universe; though this destructive force also can be demonic, imagery is the left arm.
Tipheret - ideal balance of Justice and Mercy, masculine.
Netzah - Eternity; God's grace, also endurance and victory.
Hod - Glory; associated with prophecy, it is God's judgment into the world.
Yesod - Foundation; a medium for creative and divine forces (phallus imagery).
Malkut / Shechinah - Kingdom / God's Presence; while having no special attributes, it can be used as a medium where all the nine other Sefirots can be chnanneled into the created world.
It's a little amazing to find some realistic level of comparison between the Sefirots, and the FF7 series. There are nine playable characters in the game (Cloud Strife, Tifa Lockhart, Aeris Gainsborough, Barrett Wallace, Yuffie Kisaragi, Cid Highwind, Red XIII, Vincent Valentine, and Cait Sith) resembling the nine Sefirots. The tenth Sefirot Malkut, in which the other attributes of the Nine Sefirots can be channeled through, is Sephiroth, who is a playable character for a brief time during the Nibelheim flashbacks. Malkut actually exists alone, depciting the harmony of the other nine Sefirots. This could also mean that if not for Sephiroth, these nine other characters would not have banded together against him.
Vincent Valentine as the Din Sefirot
Something else in the Kabbalah that Vincent Valentine fans might appreciate; the Sefirot called Din or Geburah is known as God's Justice. It seeks to ensure that justice and divine punishment is wrought out in the overall scheme of things, but this force can also be demonic in nature. The symbol of Din is the left arm. Remember that Vincent is out both to atone for the "crime" that he had committed (letting Lucretia be injected with the JENOVA cells, thereby endangering her life), and to seek vengance for the man responsible for Lucretia's pain, Hojo. This seemes to jive well with "justice and divine punishment" that Vincent sets out to do. Also, Din warns that the destructive forces that taper it may be demonic in nature; we know that Vincent has been subjected to Hojo's experiments and had been injected with JENOVA cells and monster serum. One of his main limit breaks include the ability to transform into a monster, which again may seem "demonic". And finally, the symbol for the Din is the left arm; remember again that Vincent's left arm had been rendered useless due to all his mutations and experiments being done on him. It's quite possible that when Square created FF7, Vincent was what they had in mind for the Din. (although if it is a coincidence, it's a HUGE coincidence)