This article explores inter- and transdisciplinarity, given the need for more complex, relevant, and transformative knowledge to shift society towards more sustainable futures. It connects practical questions about economic, societal, and ecological limits to questions about the limitations of academic knowledge. Transdisciplinarity involves co-constructing socially relevant, transformative knowledge with actors outside academia. In practice, transdisciplinary work requires clarity about intentions, along with inclusive and well-facilitated collaborative processes that accommodate dissenting and transgressive perspectives. Higher education has begun to experiment with inter- and transdisciplinarity via sustainability-focused projects. However, it insufficiently addresses broader demands for transformation and cannot address these adequately without integral leadership.