Keizo Matsubara is a philosopher and physicist. He received a PhD in theoretical physics from Uppsala University in 2004. After this Keizo started studying philosophy and became a researcher in a project on philosophical aspects of string theory. This research led to Keizo receiving a second PhD from Uppsala University in 2013, this time in philosophy. Following this he had a two-year position as Postdoctoral fellow in the Philosophy of the Foundations of Physics at Rotman Institute of Philosophy. Keizo is now a Visiting Postdoctoral Research Associate working within the project Space and Time after Quantum Gravity.