  But it is important to point out that the work on causality discussed  in  Section 4.6  and Pearl’s ideas do share some common themes. On both approaches: action is central for causality. Also there is a focus on causality as a tool in reasoning that is necessitated in part by limited resources. Another important theme is the deployment and systematic study of formalisms in which causality is related to other constructs (in particular, to probability and to qualitative change) and a variety of realistic reasoning problems are addressed.