Considerable confusion surrounds the notion of 'subliminal perception'. While empirical findings from subliminal perception experiments appear to demonstrate that subliminal perception can both occur and lead to a variety of (often dramatic) effects, the present conceptualisations of subliminal perception are problematic since they fail to clarify specifically what is, and is not, known when perceiving subliminally. Consequently, accounts of subliminal perception are vulnerable to sceptical disbelief and criticism, since the coherency of the theoretical framework has not been adequately established. This paper reviews the current accounts and evidence of subliminal perception and proposes a framework for clarifying existing thinking. 'Knowing' is discussed as a relation between a cognising subject and a cognised object term, which provides a platform for clarifying the questions concerning the subject and object terms involved when discussing subliminal perception. On this view, in knowing one does not automatically know that one knows (ie, one can know something without having knowledge of knowing it). Furthermore" 'becoming conscious' (knowing that one knows) requires a second mental act, independent of the first act of knowing. This theoretical position unifies the competing accounts of subliminal perception, and provides a clear conceptualisation of perception and its objects when perceiving sublimely. Additionally, this account provides an avenue for investigating experimental manipulations of subliminal perception, as well as explaining why subliminal stimuli presentations and not supraliminal ones, lead to the specific variety of empirical findings found in subliminal perception research. Directions for future research based on this approach are discussed.