The nature of design ontology continues to be explored as a crucial step in building closer relationships between the domains of the sciences, arts & humanities, and design. We focus thinking by design researchers including the co-authors to question the true nature of design ontology and its relationship to time, core design practices, reliability, and collaboration across domains. We examine how temporal relationships can drive a new definition of core domain level practices via an examination of Archer’s wroughting and wrighting as core practices for design. Our exploration identifies transferability as being the ontological essence of design. However, this raises serious problems in terms of rigour and reliability. We propose an ontological mirror that explains the diverse nature of design while addressing serious rigour issues. This formally positions design as knowledge for future transformation.