I Am a Strange Loop - Douglas R. Hofstadter [110]
Of Hogs, Dogs, and Bogs
If you wish to understand what goes on in a biological cell, you have to learn to think on this new informational level. Physics alone, although theoretically sufficient, just won’t cut it in terms of feasibility. Obviously the elementary particles take care of themselves, not caring at all about the informational levels of biomolecules (let alone about human perceptual categories or abstract beliefs or “I”-ness or patriotism or the burning desire, on the part of a particular large agglomeration of biomolecules, to compose a set of twenty-four preludes and fugues). Out of all these elementary particles doing their microscopic things, there emerge the macroscopic events that befall a bio-creature.
However, as I pointed out before, if you choose to focus on the particle level, then you cannot draw neat boundary lines separating an entity such as a cell or a hog from the rest of the world in which it resides. Notions like “cell” or “hog” aren’t relevant at that far lower level. The laws of particle physics don’t respect such notions as “hog”, “cell”, “gene”, or “genetic code”, or even the notion of “amino acid”. The laws of particle physics involve only particles, and larger macroscopic boundaries drawn for the convenience of thinking beings are no more relevant to them than votingprecinct boundaries are to butterflies. Electrons, photons, neutrinos, and so forth zip across such artificial boundaries without the least compunction.
If you go the particles route, then you are committed to doing so whole hog, which unfortunately means going way beyond the hog. It entails taking into account all the particles in all the members of the hog’s family, all the particles in the barn it lives in, in the mud it wallows in, in the farmer who feeds it, in the atmosphere it breathes, in the raindrops that fall on it, in the cumulo-nimbus clouds from which those drops fall, in the thunderclaps that make the hog’s eardrums reverberate, in the whole of the earth, in the whole of the sun, in the cosmic background radiation pervading the entire universe and stretching back in time to the Big Bang, and on and on. This is far too large a task for finite folks like us, and so we have to settle for a compromise, which is to look at things at a less inclusive, less detailed level, but (fortunately for us) a more insight-providing level, namely the informational level.
At that level, biologists talk about and think about what genes stand for, rather than focusing on their traditional physico-chemical properties. And they implicitly accept the fact that this new, “leaner and meaner” way of talking suggests that genes, thanks to their informational qualities, have their own causal properties — or in other words, that certain extremely abstract large-scale events or states of affairs (for example, the high-level regularity that golden retrievers tend to be very gentle and friendly) can validly be attributed to meanings of molecules.
To people who deal directly in dogs and not in molecular biology, this kind of thing is taken for granted. Dog folks talk all the time about the temperamental and mental propensities of this or that breed, as if all this were somehow completely detached from the physics and chemistry of DNA (not to mention physical levels finer than that of DNA), and as if it resided purely at the abstract level of “character traits of dog breeds”. And the marvelous thing is that dog folks, no less than molecular biologists, can get along perfectly well thinking and talking this way. It actually works! Indeed, if they (or molecular biologists) tried to do it the pure-physics way or the pure-molecular-biology way, they would instantly get bogged down in the infinite detail of unimaginable