Complex sentence: Paul Williams acknowledges Gethin's suggestion of the "principle of the equivalence of cosmology and psychology," but notes that Gethin is not asserting the Buddhist cosmology is really all about current or potential states of mind or psychology.
Split into simpler sentences: Paul Williams acknowledges Gethin's suggestion of the' principle of the equivalence of cosmology and psychology. ' However, Williams then notes that Gethin is not asserting the Buddhist cosmology is really all about current or potential states of mind or psychology.