There are many theories which have been discovered or invented throughout human history, which to various people could be considered to "explain everything".

Some of these theories have gone on to become increasingly well supported by further evidence. Others have been proven incorrect, discarded, superseded, forgotten, and so forth. I'm interested in all categories of theory.

Example Theories

I'm not going to say whether or not these theories fit the first category or the second category. But here are some examples, that to either their inventors or their followers, can be seen to explain "everything" where everything may not mean the entirety of existence but certainly something far larger than a single human.

• Euclidian geometry
• Atomic theory
• Newtonian physics
• Classical economics
• Microscopy
• The theory of evolution
• Freudian analysis
• Plato's cave
• Quantum physics
• Game theory
• Statistics
• Cellular automata
• The simulation hypothesis
• The Gaia hypothesis
• Any religion
• Any artform
• Any conspiracy theory
• All of psychedelia
• All literature
• Polygons
• Talking and non-talking animals
• Theories of history, includes historical theories of history etc.
• Each individual Bob Dylan album.

William Blake

If memory serves, an English poet geezer name of William Blake wrote Auguries of Innocence and it went something like this:

To see a world in a grain of sand
And a heaven in a wild flower,
Hold infinity in the palm of your hand
And eternity in an hour.

And so: each theoretician or followerer of a theory, is inspecting something so small, so reduced, that it can be imprinted within a grain of sand, and is worth no more than a speck of dust -- yet, when studied by them, through their eyes -- what is seen is a recreation of the entire universe from the dawn of time until its conclusion.

So it is with any one, having connected as few as two concepts, within the privacy of their own mind. All seems extraordinary.

References

• Auguries of Innocence | The Poetry Foundation

See also