The following quotation sums up his philosophy admirably:
It has long been my personal view that the separation of practical and theoretical work is artificial and injurious. Much of the practical work done in computing, both in software and in hardware design, is unsound and clumsy because the people who do it have not any clear understanding of the fundamental design principles of their work. Most of the abstract mathematical and theoretical work is sterile because it has no point of contact with real computing. One of the central aims of the Programming Research Group as a teaching and research group has been to set up an atmosphere in which this separation cannot happen.
For an authoritative account of Strachey's life and work, see:
Christopher Strachey, 1916-1975 - A Biographical Note, Martin Campbell-Kelly. Annals of the History of Computing, Vol.7, No.1, pp.19-42, 1985.The April 2000 issue of Higher-Order and Symbolic Computation (Volume 13, Issue 1/2) was dedicated to the memory of Christopher Strachey, 25 years after his passing away, and includes his previously unpublished lecture notes "Fundamental Concepts in Programming Languages".