Dennis Lindley, who has died aged 90, was one of the modern founders of the "Bayesian" school of statistics, an approach to inference that has had a dramatic effect on how we analyse data. Our increasing reliance on quantitative evidence when making decisions means that this work has had a vast impact – in medicine, commerce, science, and indeed in just about all walks of life.
Lindley said his aim in his early years as an academic was to make statistics a respectable branch of mathematics: all the other courses he had studied had the classic mathematical form, of a system of axioms from which the consequences were deduced, but statistics lacked this. As a consequence, Lindley initially saw his work as providing a solid mathematical base for the then dominant frequentist school of statistics, and only later recognised that in fact he had produced something rather different.