In Celtic-Germanic folklore, the Norns weave together the threading paths of all life and spacetime, including for humanity, families of humanity, tribes, clans, a lifeforce experiencing lifetimes, or of a single lifetime walking its paths of life. The Celtic Tree of Life is a visual representation of the interconnectedness of all of these ways of experiencing consciousness.
In Jewish and Western Occult Kabbalah, there is a distinction made between a derekh (a broad road used by many people) and the netivot (smaller and unique routes). A derekh can have many levels of meaning. For example, the tree trunk can represent all life from the perspective of all lifeforms, with branches diverging into the ever increasing uniqueness characteristic of the diversity of lifeforms on the earth (and within the cosmos). From the perspective of humanity, the trunk of the tree represents our common humanity.
As human incarnations of the Lifeforce of the cosmos, we are not the same. Individuation is growth. As Homo sapiens sapiens humans, we are a branch on humanity's specific tree of life, our own branch itself woven from many species of humanity. As humanity continues to evolve and to branch out into different species of humanity, subspecies of humanity, families of humanity, tribes, clans, a lifeforce experiencing lifetimes or a single lifetime, we are individuating, we are growing, we are accumulating diverse conscious experience.
As a particular human lifeforce experiencing many lifetimes, one's particular measure of human lifeforce over lifetimes can also be represented by the trunk of the tree of life. As we experience our lifetimes, we weave together those experiences into an tapestry of consciousness unique to the experiences of our particular ever-individuating measure of lifeforce. The ancient Celts understood the importance of individuation to evolving consciousness - to humanity, families of humanity, clans, tribes, the lifeforce experiencing lifetimes, and to each individual lifetime.
Others are necessary for the evolution of consciousness. Without others, there is no tapestry. Without others, there is no consciousness. Our particular cosmos is itself a woven structure. The so-named Big Bang can also be likened to the tree trunk, with branches extending from it into a myriad of Other cosmoi. The defining aspect of all evolving cosmoi, consciousness, and life itself, is thus, Otherness. The unchanging common essential core (the trunk) is part of Nature, not separate from it, and connects All. Evolving yet simultaneously unchanging - this concept, represented by the Celtic Tree of Life, is known metaphysically as unity in multiplicity.