There are two origins of the phrase
“everything is in everything.”
If everything is actually in everything, then there are infinite origins of the idea, with everything also being the origin (though not the cause) of everything else. The chicken and the egg are both one and the same. But our minds are limited, so let’s play pretend there are two prime philosophical sources: one Greek, one French.
The first was a philosopher named Anaxogoras, who lived in the 5th century B.C.E. In his unique-for-his-time metaphysical framework, he theorized that everything in the cosmos was made of different combinations of the same “ingredients,” that all things contained the same stuff, but in different configurations. Even completely different, unrelated things contained seeds of one another. What made each thing different was only how they were animated by the mind.
Much later, in the 1980’s of the Current Era, the philosopher Jacques Rancière used the phrase “everything is in everything” when writing about intellectual emancipation. He argued that we cannot be liberated from class oppression if hierarchies of knowledge and expertise are maintained in educational environments. His proposal was for the pedagogy of “universal teaching,” the basic principle of which was to learn something and relate everything else to it, because "everything is in everything.” Every word, poem, piece of history, mathematical formula needs the entirety of the world to exist, and so contains everything else in it. You can literally start anywhere, and discover connections to everywhere else. Universal teaching is not about teaching to the lowest common denominator of prior knowledge. Universal teaching is the awareness that the universe is actually doing the teaching. Together, we are just partial interpreters of the infinite web.
In 2017, the Irish media artist David O’Reilly released a video game called Everything. In this simulation game, the player begins as one of the many possible creatures on Earth and has the ability to shift their point of view or player agency into smaller and smaller parts of matter, down to subatomic particles, and eventually to larger ones, up to planets and universes in scale. The game is an interactive realization of the “everything is in everything” concept. Below is a trailer for the game, with narration by Alan Watts, a mystic and philosopher of universal interconnectedness. So see, I lied, already there are more than two. How many are there?