Rigid/non-rigid grounding and transitivity

While extant replies to Jonathan Schaffer's putative counterexamples to the transitivity of grounding have made significant strides against the charge of transitivity failure, the replies pay insufficient attention to the common structure of the counterexamples, overlooking a deeper structural feature that contributes to their prima facie plausibility. Putative counterexamples to the transitivity of grounding, I argue, trade on the distinction between what I call 'rigid' and 'non-rigid' grounding, and confusion over how rigid and non-rigid grounding react when combined pumps the intuition that the counterexamples' chained conclusions are false. The rigid/non-rigid grounding distinction also reveals plausible weakening inference rules that have been overlooked in treatments of the logic of grounding.