[madhadron]

The other side of this is: what constitutes an explanation? What formal structure that you express observations in seems like knowing what's going on to you? Formal structures in fields tend to be matched to what the experimental abilities of the field are.

In programming, we designed our systems to give us what seem like hard bottoms in our formal models. Most programmers don't reason below the level of their structured programming language. Of the ones that do, most treat the processor instructions as a hard bottom. There are layers down and down until you have physicists working on semiconductor properties, but we have intentionally designed the layers so that you can comfortably rest on them.

In biology any formal structure you think in is logically poised over the abyss. What pins it in place is not that it is on philosophical bedrock, but the observations and experiments that the formal structure summarizes.