The Great Equation

The Fleet Of Stars, 19.

"The great equation from which every law of physics could be derived was in existence." (p. 235)

Later, new data indicate that the great equation is incomplete. 

As I understand it, a Theory of Everything would:

be mathematical in form, a single equation;

describe the most fundamental properties of the most fundamental entities;

unify the forces of nature;

be a single premise from which the familiar laws of physics and chemistry could be deduced;

would not be a basis from which history or contingent events could be deduced.

Would it answer the mind-body question?

Even if a ToE had been formulated, how would it be known that no new data would ever contradict it?

There is a philosophy according to which every theory is provisional, always to be superseded by another theory that explains more. This seems intuitively valid.