The scientiﬁc and ethical context
Most clinical psychologists see themselves as being part of a scientiﬁc intellectual tradition. This has its roots in the 17th century, with Galileo and other scientists who dedicated themselves to establishing the truth through observation. In the following century, David Hume suggested the centrality, not just of observation, but of the ideas of cause and effect, in helping us understand phenomena:
Here is a billiard ball lying on the table, and another ball moving toward it with rapidity. They strike; and the ball which was formerly at rest now acquires a motion. This is as perfect an instance of the relation of cause and effect as any which we know either by sensation or reﬂection.