The word nephesh occurs 754 times in the Hebrew Bible. The first four times nephesh is used in the Bible, it is used exclusively to describe animals: Gen 1:20 (sea life), Gen 1:21 (great sea life), Gen 1:24 (land creatures), Gen 1:30 (birds and land creatures). At Gen 2:7 nephesh is used as description of man.
Job 12:7-10 offers a distinct similarity between רוח (ruah) and נפׁש (nephesh): “In His hand is the life (nephesh) of every living thing and the spirit (ruah) of every human being.” (Wikipedia)
Let's test my theory against the scriptures.
[Judah speaking:] Now therefore when I come to thy eved Avi, and the na’ar [Benjamin] be not with us; seeing that his nefesh [Judah’s soul] is bound up in the nefesh of the na’ar [Benjamin’s soul]; Genesis 44:30 (OJB) [Our souls may become intertwined with kids, spouses and pets; but our neshamah remains separate and intact.]
My son, obey your father’s command [Torah], and don’t abandon
your mother’s teaching [Torah]. For the mitzvah [loving/living the Torah, which
is Jesus] is a lamp, Torah is light, and reproofs that discipline are the way
to life. Proverbs 6:20, 23 (CJB)
Death: The nephesh that sinneth, it shall die Ezekiel 18:20 (OJB) Or ever the silver cord be loosed [our DNA seems to be like a silver cord. Does it loosen when we die?], or the golden bowl be broken, or the pitcher be broken at the fountain, or the wheel broken at the bor (cistern). Then shall the aphar [dust] return to ha’aretz [earth] as it was; and the ruach shall return unto HaElohim who gave it. Ecclesiastes 12:6-7 (OJB)
My final opinions: Life is the Revelation of God to the world, whereby some of the primordial light is [veiled] under the throne of glory for a time and a season until it is time to completely shine forth. Jesus is the Torah, which is a light veiled from Christianity. Likewise, the Torah is Jesus, which is a light veiled from Judaism. He was fully God and fully man. Humans and animals are not God. All we know about life is what has been described in the Bible. Life for humans is Jesus! And, as for animals…