Howie Firth's greetings to Dick Sillitto

I think that of all the skills that we need to draw upon in life and in science, clarity of thought is up there at the very top, and Dick Sillitto’s teaching simply glows with it.

In his classes in geometrical optics at Edinburgh, he built up the concepts step by step, carefully defining his terms, highlighting areas where notation could vary, and making sure that we all could follow where we were coming from and where we were going. It was all so superbly clear, and also utterly fascinating.

It was only later that I discovered that courses in geometrical optics were not necessarily always like this, in a subject containing a variety of potential sources of confusion in notation and concepts; and that by contrast to what might have been, those of us who had been taught by him had had the privilege of learning from a highly gifted lecturer.

Still later, I discovered that I had learned from him not only how to understand geometrical optics, but also how to approach the understanding of any subject; and how to communicate it. It was not only the facts that we absorbed, but a whole way of thinking.

Descartes set out the method, of building upwards from the base, laying the foundations and moving up layer by layer, and Dick’s teaching epitomises the method at its best. Indeed, I think that the great philosopher who spent so many years out on the road travelling would have enjoyed a visit to Dunbar, to walk along the cliffs and the shore with Dick and Winifred and to exchange thoughts about science past and present; and indeed also to hear about the ideas of John Muir, whose understanding of the sea and the mountains and the forests so revives and refreshes.

So here’s the warmest of greetings on your birthday, Dick. May the glasses clink joyfully, the conversation sparkle, and plans and ideas bubble up like champagne!

Howie