The paper considers the statistical work of the physicist Harold
Jeffreys. In 1933-4 Jeffreys had a controversy with R.A. Fisher, the
leading statistician of the time. Prior to the encounter, Jeffreys had
worked on probability as the basis for scientific inference and had used
methods from the theory of errors in astronomy and seismology. He had also
started to rework the theory of errors on the basis of his theory of
probability. After the encounter Jeffreys produced a full-scale Bayesian
treatment of statistics in the form of his Theory of Probability.