 We need something stricter than just “an explanatory role” to identify grounding—otherwise we would end up with a much too liberal notion, for we may regard a number of loosely connected things explanatory in some very loose sense. For instance, we might say that the fact that Smith murdered Jones is explained by certain events in Smith’s childhood, but a more direct explanation might be Smith’s desire to rob Jones. Certain events in Smith’s childhood may help us understand why Smith has murderous desires, but it’s not clear that they serve to ground the fact that Smith murdered Jones (unless we can establish transitivity between these).