  This, however, seems to be not as radical a metaphysical thesis as talk of downward causation may initially suggest. Indeed, Soto and Sonnenschein seem to simply refer to a form of constraint. Green (2019) takes “downward causation” to mean just this: “the role of solid-state tissue properties in tumor progression can be interpreted as a form of downward causation, understood as constraining relations between tissue-scale and micro-scale variables” (p. 1). She notes that while this suggestion is “a ‘weaker’ form of downwards causation than the one Kim (2000) and others oppose,” and so departs from standard use of the expression (at least among philosophers of mind), the advantage of this weaker notion that it better captures what scientists have in mind when arguing for the “necessity of higher-scale features for the realization and understanding of biological phenomena.” Similarly, Bertolaso (2016) argues that: