2025 Volume 24 Pages 70-83
In the field of second language acquisition, linguistic knowledge has traditionally been classified into two dichotomous categories: what can be utilized consciously (hereafter, conscious knowledge) and unconsciously (unconscious knowledge), and the distinction has been a focus of active debates for decades. This paper broadly introduces such frameworks concerning conscious and unconscious knowledge in second language acquisition, highlighting the historical developments in this area of research. Additionally, these traditional frameworks are examined to show that the dichotomies presented so far seem to be about the same constructs but actually are different, and that different interpretations and predictions of the same phenomenon can arise depending on the framework on which they are based. In the end, I suggest that theories about the consciousness inherent in knowledge are potentially relevant to research based on any linguistic theory, as long as it studies a second language. It is then shown that this theoretical study of consciousness requires a logic of inquiry similar to that of linguistic theory, and future perspectives are discussed.