Explanatory Gaps as a Guide to Reality

The world seems to be ordered into levels. According to this intuitive picture, some things are more fundamental than others. The more fundamental things ground the less fundamental things. Lego bricks ground Lego castles, the parts of tables ground tables, and grains of sand ground heaps of sand. This project has two main goals. First, it aims to understand what it means for the more fundamental to ground the less fundamental. Second, it aims to investigate whether we can discover what grounds what from the clarity of grounding connections. In ordinary life, the connections between the more and less fundamental seem clear. There seems to be no mystery regarding how Lego bricks ground Lego castles, how the parts of tables ground tables, or how grains of sand ground heaps of sand. In all these casesand countless others involving ordinary objects and their partsthe more fundamental seems to fully and clearly explain the less fundamental. Taken all the way, the above idea leads to a picture of reality where, in all cases of grounding, the more fundamental clearly explains the less fundamental. But is this picture plausible? And if it is, what can we learn about reality from any potential exceptions to this picture? I call the lack of clear explanation in a proposed case of grounding an explanatory gap. The most famous example of a potential explanatory gap concerns consciousness and the brain. Many researchers think that the brain grounds consciousness. Yet, the connection between the brain and consciousness seems mysterious and opaque. This has led some researchers to doubt that the brain grounds consciousness. In their view, consciousness cannot be material if consciousness lacks a material explanation. The case of consciousness shows that explanatory gaps, at least in some cases, might be a reason to rethink what grounds what. Contemporary philosophers, often inspired by physics, have proposed many theories of what is fundamental. One way to test these ideas is by considering explanatory gaps. Doing so requires a better understating of grounding, explanatory gaps, and the significance of explanatory gaps for grounding. In a nutshell: explanatory gaps might be a guide to realitys levels. If so, explanatory gaps matter, and we should try to understand them better.