Commensurability 1.0
My MPhil thesis was concerned with moving towards an "empirical" theory of ethics. The details of this project are no longer important, but what was recognised as a contribution from my thesis by the supervisors was a discussion of what I called commensurability.
The word "commensurability" has been used in several different senses in philosophy. I was specifically using it to mean "conduciveness towards a non-coercive convergence of opinion (through rational discourse)", of which I currently distinguish six levels:
Level 1 is triviality, and concerns claims about which there is an already existing convergence of opinion. The claims of commonsense are at level 1, such as, "The sky is blue", "The pope is Catholic", "1 + 1 = 2", etc.
Level 2 is agreeability. Level 2 claims are claims about which a non-coercive convergence of opinion seems clearly possible through rational discourse. The claims of science are at level 2 because the scientific method conduces to non-coercive agreement so very powerfully, and in fact any claim that does not meet level 2 would be considered unscientific.
Level 3 is respectability. Level 3 claims are such that a non-coercive convergence of opinion does not seem possible about them, but that one may nevertheless be able to form good arguments for them. The claims of philosophy are at level 3, because philosophy consists of many schools, which cannot seem to reach agreement on general issues, but which can nevertheless gain respectability with each other. Any claim that one cannot make respectable through adequate argument cannot be considered of philosophical merit.
Level 4 is appreciability. Level 4 claims are such that one might not be able to make them respectable, but one can at least appreciate why one would want to hold such a view. The claims of religion are, arguably, at level 4, because although one cannot necessarily argue cogently for them, one can still appreciate the reasons for believing in them. Conversely, a claim that is not at level 4 is absurd, to be dismissed offhand. If someone said that the moon were made of green cheese, for example, one would not see geologists jumping up to refute her, because the view lacks appreciability.
Level 5 is comprehensibility. Level 5 claims are such that although one cannot necessarily appreciate them, one can at least comprehend what they mean. If someone says that the moon is made of green cheese, we would not argue with him about it on the grounds that his claim is absurd. But in order to arrive at the conclusion that such a claim is absurd, we must have understood the claim to begin with, which still implies some weak form of commensurability. Some claims are such, however, that we would not argue for or against them, simply because we cannot argue them in the first place, because we do not comprehend them. For example, courts have refused to enforce some contracts on the grounds that neither side properly comprehends them.
Level 6 is thematicity. Level 6 claims are such that although one cannot necessarily comprehend them, there is actually a claim in there somewhere to comprehend. A legal document should be at least at level 6 because, presumably, it has at least been written with a clear intention in mind of what it means. If it has been poorly written, this intention will not be clear to its audience, but presumably there was at least once an actual claim that someone had meant to make. Someone else who understands the way the author thinks might be able to infer this claim correctly. On the other hand, a piece of writing produced by monkeys typing randomly on a keyboard will not provide fruitful analysis, even if one manages to "infer" a view from it. This is because there was no intentional thematicity to the writing in the first place that could form the basis for a claim.
It is not clear whether 6 is the only possible number of divisions for different levels of commensurability. However, one can define the absolute maximum and minimum limits for commensurability. Level 1 is the maximum limit because one cannot get any more conducive towards a non-coercive convergence of opinion than a claim about which convergence already exists. Level 6 is the minimum limit, because without having a claim at all, no convergence of opinion is possible in the first place.
Note that one can clearly construct a converse scale of levels of incommensurability. Hence, level 1 incommensurability is the same as the absence of level 6 commensurability, level 2 incommensurability is the absence of level 5 commensurability, and so on.
The word "commensurability" has been used in several different senses in philosophy. I was specifically using it to mean "conduciveness towards a non-coercive convergence of opinion (through rational discourse)", of which I currently distinguish six levels:
Level 1 is triviality, and concerns claims about which there is an already existing convergence of opinion. The claims of commonsense are at level 1, such as, "The sky is blue", "The pope is Catholic", "1 + 1 = 2", etc.
Level 2 is agreeability. Level 2 claims are claims about which a non-coercive convergence of opinion seems clearly possible through rational discourse. The claims of science are at level 2 because the scientific method conduces to non-coercive agreement so very powerfully, and in fact any claim that does not meet level 2 would be considered unscientific.
Level 3 is respectability. Level 3 claims are such that a non-coercive convergence of opinion does not seem possible about them, but that one may nevertheless be able to form good arguments for them. The claims of philosophy are at level 3, because philosophy consists of many schools, which cannot seem to reach agreement on general issues, but which can nevertheless gain respectability with each other. Any claim that one cannot make respectable through adequate argument cannot be considered of philosophical merit.
Level 4 is appreciability. Level 4 claims are such that one might not be able to make them respectable, but one can at least appreciate why one would want to hold such a view. The claims of religion are, arguably, at level 4, because although one cannot necessarily argue cogently for them, one can still appreciate the reasons for believing in them. Conversely, a claim that is not at level 4 is absurd, to be dismissed offhand. If someone said that the moon were made of green cheese, for example, one would not see geologists jumping up to refute her, because the view lacks appreciability.
Level 5 is comprehensibility. Level 5 claims are such that although one cannot necessarily appreciate them, one can at least comprehend what they mean. If someone says that the moon is made of green cheese, we would not argue with him about it on the grounds that his claim is absurd. But in order to arrive at the conclusion that such a claim is absurd, we must have understood the claim to begin with, which still implies some weak form of commensurability. Some claims are such, however, that we would not argue for or against them, simply because we cannot argue them in the first place, because we do not comprehend them. For example, courts have refused to enforce some contracts on the grounds that neither side properly comprehends them.
Level 6 is thematicity. Level 6 claims are such that although one cannot necessarily comprehend them, there is actually a claim in there somewhere to comprehend. A legal document should be at least at level 6 because, presumably, it has at least been written with a clear intention in mind of what it means. If it has been poorly written, this intention will not be clear to its audience, but presumably there was at least once an actual claim that someone had meant to make. Someone else who understands the way the author thinks might be able to infer this claim correctly. On the other hand, a piece of writing produced by monkeys typing randomly on a keyboard will not provide fruitful analysis, even if one manages to "infer" a view from it. This is because there was no intentional thematicity to the writing in the first place that could form the basis for a claim.
It is not clear whether 6 is the only possible number of divisions for different levels of commensurability. However, one can define the absolute maximum and minimum limits for commensurability. Level 1 is the maximum limit because one cannot get any more conducive towards a non-coercive convergence of opinion than a claim about which convergence already exists. Level 6 is the minimum limit, because without having a claim at all, no convergence of opinion is possible in the first place.
Note that one can clearly construct a converse scale of levels of incommensurability. Hence, level 1 incommensurability is the same as the absence of level 6 commensurability, level 2 incommensurability is the absence of level 5 commensurability, and so on.
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