 Popper’s demarcation criterion concerns the logical structure of theories. Imre Lakatos described this criterion as “a rather stunning one. A theory may be scientific even if there is not a shred of evidence in its favour, and it may be pseudoscientific even if all the available evidence is in its favour. That is, the scientific or non-scientific character of a theory can be determined independently of the facts” (Lakatos 1981, 117).