This article suggests to reflect on the philosophical foundations of Open Education. It reaches out to Bergson's and Popper's respective understandings of Open Society; ontology of immanence, not-yetness; and post-inquiry. It invites to revisit "ethos," "eidos" and "praxis" in Open Education to move away from a prevailing Western, dominant, unsustainable paradigm and explore a holistic approach, the inclusion of indigenous knowledge systems, the shift from an overall domesticating to a liberating education, and the making visible of what has been made invisible. This discussion precedes the presentation of a roadmap drafted for Open Education in the Swiss Higher Education landscape, explaining why it has been deliberately prepared at the epistemic level and how relevant this is in relation to the sustainability process, providing a horizon for the first of three steps -- survival, security, sustainability.