But some philosophers conclude that functionalism is a good theory of intentional states but that it nevertheless fails because it cannot explain other sorts of mental states—in particular, they say that it cannot explain sensations and other conscious mental states.

What is the problem with functionalism?

Functionalism does not claim that every mental system has a machine table of a sort that justifies attributions of mentality with respect to every specification of inputs and outputs, but rather, only with respect to some specification.

Why does functionalism no longer exist?

Functionalism posits that society is more than the sum of its parts; rather, each aspect of it works for the stability of the whole. ... According to functionalism, an institution only exists because it serves a vital role in the functioning of society. If it no longer serves a role, an institution will die away.