10. The above express primary findings of fact made by the learned trial judge did not, however, suffice to provide an answer to the question whether, for relevant purposes, the premature termination of the plaintiff's University appointment had been caused by the injuries which the plaintiff had sustained in the relevant accident. Clearly enough, the chronic and sometimes intense pain, the nightly disturbance of sleep and the associated loss of "intellectual energy" which his Honour found resulted from the plaintiff's injuries had caused some diminution in his earning capacity. The plaintiff's evidence, if accepted, supported a conclusion that, accepting the findings of the trial judge, those effects of his injuries were a causative influence in the premature termination of his employment in two distinct ways. First, they were a contributing cause of his decision to retire in that their effect was to decrease his ability to discharge the duties of his appointment at what he saw as an acceptable standard. That is to say, they were a contributing cause of what his Honour found to have been a subsidiary "reason for the plaintiff's early retirement". Secondly, and more importantly for present purposes, they were also a contributing cause of what his Honour found to have been the "pre-eminent" reason why the plaintiff decided to retire early", namely, a desire "to devote as much time as possible to research and creative philosophy untroubled by the requirements of University life and in particular the administration and teaching duties required of him". As we read the whole of the plaintiff's evidence, including a letter of 26 May 1987 upon which both the trial judge and the members of the Full Court placed particular reliance, the plaintiff's case was to the effect that the pain, fatigue and loss of intellectual energy caused by the accident had led to a situation where the discharge of his administrative and teaching duties absorbed much more of his time and capacity than would otherwise have been the case and precluded him from doing the research and creative work which he would otherwise have been able to do: as he wrote in that letter, teaching "uses up all the energy I have available. Non-teaching periods of the year are mostly consumed by teaching - either preparation or recovery." That being so, the trial judge's findings that the "pre-eminent reason why the plaintiff decided to retire early was to be able to devote as much time as possible to research and creative philosophy" and that a subsidiary reason for early retirement was that the plaintiff believed he should retire for the reason that "he was not performing at the level he thought desirable" did not suffice to answer any question of causation in the present case. Rather, those findings gave rise to the question whether, taking account of any part played by the plaintiff's injuries as a contributing cause of each of those reasons, it should be concluded that the plaintiff's premature retirement was, for relevant purposes, caused by the accident in the sense that it was a product of the loss of his earning capacity resulting from the injuries which he had received in it. His Honour did not expressly deal with that question or with the combined significance of those different causative effects.