John Searle has devoted critical attention to the concept of unconscious mental phenomena as one strand of his well-known program directed against certain features of cognitive science. Searle is concerned to show that all unconscious intentional states are in principle accessible to consciousness, referring to this dictum as the "connection principle". According to this view, unconscious states are only "mental" by virtue of their causal powers to produce (truly mental) conscious states. They are, as it were, derivatively mental.