>>13003501Neoplatonism: new Platonic school by Plotinus ended by Justinian.
Perennial philosophy has its roots in the Renaissance neoplatonism and its idea of the One.
These ideas became relevant in the early 20th century as the Traditionalist school formed the philosophical underpinnings of fascist Italy via thinkers such as Rene Guenon and Jules Evola.
Such ideas can help found the basis of ethic antithetical to modernity and its neoliberal world order. These machinations are unpopular not due to their lack of merit or inability to stand up to logical and philosophical scrutiny, but merely because they are unpalatable. Karl Popper, the neolibral philosophical hero your world view came from, calls such thinking extremely dangerous.