Both Rockwell, (2005), and Hurley, (forthcoming), express skepticism about the coupling-constitution distinction, although neither express serious reasons for doubting the distinction. There is, it seems to us, some reason for their suspicion, namely, that it is hard to make out this distinction for the case of cognition. What is the difference between things that merely cause cognitive processes and things that constitute cognitive processes? If we restate the question slightly, the source of the difficulty should be clear. What, we should ask, is the difference between things that merely cause cognitive processes and things are cognitive processes? The problem lies in the uncertainty about what exactly cognitive processes are. In support of this diagnosis, consider a case where we do have a well-established theory of what a given type of process is. Consider again the process of nuclear fission. The process of nuclear fission is constituted by the process of a large atomic nucleus being broken into smaller atomic nuclei. Nuclear fission can be caused by bombardment of the nucleus with neutrons. The process of neutron bombardment causes nuclear fission, but does not constitute nuclear fission. Consider the isomerization of the retinal component of rhodopsin in the human eye. This process is constituted by a change in the molecular structure of the retinal component from 11-cis retinal to all-trans retinal. It is typically caused by absorption of a photon. Now the distinction is intuitively clear, although possibly difficult to explicate philosophically. Where we have a clear theory of the nature of a process, we have a very fair idea of the difference between what might cause it and what might constitute it. (Adams & Aizawa, 2008, p. 101).They object to the nuclear fission example because "the literal description of nuclear fission is mathematical and incorporates no such simple intuition". (Ross and Ladyman, 2010, p. 163). Ok. So, what's the problem with the rhodopsin example?
Thursday, September 9, 2010
What's Wrong with Rhodopsin?
Looking up info for another blog post, I see that Adams and Aizawa gave another example trying to indicate what the coupling-constitution distinction might be (rather than trying to give a philosophical account of what the distinction might be). The process is the isomerization of rhodopsin upon photon capture.