Full Idea
Causal powers are often directional. For example, they may be centripetal, centrifugal, or circulatory.
Gist of Idea
Causal powers are often directional (e.g. centripetal, centrifugal, circulatory)
Source
Brian Ellis (Scientific Essentialism [2001], 3.11)
Book Reference
Ellis,Brian: 'Scientific Essentialism' [CUP 2007], p.132
A Reaction
The examples all seem to raise a few questions, about whether the directionality arises from the context, rather than from the intrinsic power.