THE RESILIENCE TRIANGLE
The state of an Earth surface system (ESS) is determined by three sets of factors: laws, place, and history. Laws (L=L1, L2, . . . , Ln) are the n general principles applicable to any such system at any time. Place factors (P=P1, P2, . . . , Pm) are the m relevant characteristics of the local or regional environment. History factors (H = H1, H2, . . . , Hq) include the previous evolutionary pathway of the ESS, its stage of development, past disturbance, and initial conditions. Geoscience investigation may focus on laws, place, or history, but ultimately all three are necessary to understand and explain ESS.
I first started using the law-place-history (LPH) framework as a pedagogic device in my teaching, and as a sort of aide memoire framework in my research. Eventually I began invoking it more explicitly in my research and writing, and expressing it formally, as in the passage above lifted from Phillips, 2018.