This paper is a phenomenological exploration of authorial intention. Aestheticians have engaged in heated debates on the role of authorial intention in art interpretation. However, the nature of authorial intention is rarely examined reflectively. In fact, it has been observed that clarification of intention occurs in art making, and this should not be overlooked. This phenomenon is not found in actions such as stopping a cab or shooting at a target. In this respect, it is interesting from the perspective of the philosophy of action and requires special treatment. This paper explores this phenomenon in terms of how it is experienced. The structure of this paper is as follows. In section 2, I highlight several descriptions of the artist's experience during art making and sketch the contour of the phenomenon that is the subject of this paper, namely, clarification of intention. According to a rough formulation, clarification of intention is a phenomenon in which an agent does not have a clear intention in advance, and clarifies the intention in the process of action. However, if the intention is not clear when the agent begins the action, how can he or she control it? In section 3, I attempt to respond to this question. Simply put, even if an artist cannot identify or describe his or her intention, he or she can make critical judgment about his or her action, and thus can control it. From this, we can see that there are two kinds of knowledge about one's intentions: knowledge-that and knowledge-how. And, in actions that involve clarification of intention, we can see two forms of knowledge-that about one's intentions: knowledge-that that can be acquired without successful completion of the action, and knowledge-that that cannot. It is not easy to grasp the difference, and this issue is explored in earnest in section 4.