more quickly or even at all. Indeed, dients themselves frequently express the view that RET is illuminating, yet they find themselves at the same time puzzled and perplexed by their inability to make the substantial changes that RET invites. It became dearer as I discussed the project with many of the contrib­ utors that to practice RET effectively requires more than just innovative and persistent assessment and intervention techniques. For example, Rus­ sell Grieger expressed the view that more prerequisite work needs to be done on the value and philosophical systems of dients-induding person­ al responsibility and the philosophy of happiness-before many dients can show significant shifts in their thinking. Susan Walen raised the gener­ al issues of how effective RET can be in the treatment of biologically driven affective disorders.