John Mason spent 40 years at the Open University, supporting students who wanted either to learn more mathematics, or to support the mathematical thinking of others. He continues in retirement to work on mathematical problems, to develop applets to help himself and others appreciate and comprehend mathematical concepts, and to respond to invitations to work with students, teachers and educators. He uses writing as a means for probing ever more deeply into the functioning of human beings in the context of mathematics teaching and learning, drawing on his own experience and observations and taking a phenomenological stance.

​Having written the equivalent of 10 or more books for the Open University on Mathematics Education, John is perhaps best known as lead author of Thinking Mathematically, in print since 1982 and described at the time of the first edition as a ‘classic’ text. He spent some 20 years articulating a way of working on oneself with colleagues (The Discipline of Noticing), trying to capture the essence of Professional Development and the ways of working used in the Centre for Mathematics Education at the Open University, and based on what he learned from J. G Bennett who was a mathematician, mystic and Teacher. He assembled Fundamental Constructs in Mathematics Education as support for teachers of mathematics who wanted to turn their concerns into research at masters level and beyond.