In philosophy, a theory of everything (ToE) is an ultimate, all-encompassing explanation or description of nature or reality.[1][2][3] Adopting the term from physics, where the search for a theory of everything is ongoing, philosophers have discussed the viability of the concept and analyzed its properties and implications.[1][2][3] Among the questions to be addressed by a philosophical theory of everything are: "Why is reality understandable?" – "Why are the laws of nature as they are?" – "Why is there anything at all?"[1]
A philosophical theory of everything, would need to, as much as is possible or makes sense, unify analytic and continental philosophy. Questions such as "Why is there anything at all?" are arguably metaphysics questions and not so much related to a philosophical ToE.