Bohm continued his work in quantum physics after his retirement, in 1987. His final work, the posthumously-published "The Undivided Universe: An Ontological Interpretation of Quantum Theory" (1993), resulted from a decades-long collaboration with Basil Hiley. He also spoke to audiences across Europe and North America on the importance of dialogue as a form of sociotherapy, a concept he borrowed from London psychiatrist and practitioner of Group Analysis Patrick de Maré, and he had a series of meetings with the Dalai Lama. He was elected Fellow of the Royal Society in 1990.