Daēnā is a multilayered concept in the Gāthās that has been interpreted in Avestan studies in terms such as seeing, insight, conscience, and religion. The research question is formulated at two interconnected levels. At the philological level, the relationship of Daēnā to choice and action is examined within the Gāthic context. At the interpretive level, the study investigates how the existentialist concepts of decision and responsibility can explain this relationship. The methodology of this study is interdisciplinary, combining a philological analysis of Daēnā and its related terms with an existentialist reading grounded in Bultmann’s hermeneutics. Linguistic evidence and philosophical interpretation remain distinct, and the limits of interpretation are determined by textual evidence. Gāthic passages, including Yasna 48:4, 51:19, and 53:5, associate Daēnā with personal acceptance, choice, and action, while eschatological passages, including Yasna 51:13, emphasize the attribution of actions and their consequences to the individual. In this regard, acceptance in connection with Daēnā in Yasna 53:5 and the attribution of actions to the individual in Yasna 51:13 are more explicit. Decision is understood as the individual's response to a possibility presented to them. Responsibility concerns being accountable for a way of living that is realized through the actions arising from it. These concepts clarify how acceptance and practical orientation involve the individual and how the consequences of actions are connected to that same individual. The originality of this article lies in applying the concepts of decision and responsibility to interpret the relationship of Daēnā to the individual's practical orientation and ultimate fate, while grounding the existentialist reading in a philological analysis of the Gāthic evidence.