Alan Mathison Turing (1912-1954) made major contributions to several areas of science. Today his name is mentioned frequently in philosophical discussions about the nature of Artificial Intelligence. He was a pioneer researcher in computer architecture and software engineering - his work in pure mathematics and mathematical logic extended considerably further. His last work was "On Morphogenesis in Plants". Turing was one of the leading figures in 20th century science, a fact which would have been known to the general public sooner but for the British Official Secrets Act, which prevented discussion of his wartime work. Although they were written decades ago, the papers in this volume address issues which concern researchers today.