Isn’t it a given that anyone with a mental impairment of any kind is less instrumentally rational [...] We don’t usually give diagnosis to people who tend to win at stuff.
I am unconvinced by the broadest versions of the “rationality = winning” thesis, for reasons I’ve mentioned to alienist elsewhere in this thread. The very broadest version (“rationality = anything conducive to winning”) would make, e.g., shortness or heart disease kinds of irrationality. A more reasonable intermediate version (“rationality = any features of one’s cognition conducive to winning”) still seems to me overbroad; it means that e.g. one person can be deemed more rational than another simply because ten years ago they happened to learn a particular language, or because they have a better (or worse) ear for music.
I think your observation that epilepsy would be deemed a variety of irrationality by the definition you’re using is actually a handy reductio ad absurdum. Do you really want to define things so that epilepsy is a variety of irrationality?
For the avoidance of doubt: I will happily agree that, all else being equal, being autistic is generally a disadvantage, and that this disadvantage is a matter of cognitive deficiencies and not only of (e.g.) prejudice on the part of others. I just don’t think “irrationality” is at all a good way to describe that disadvantage.
“Instrumentally rational” = successful on account of being epistemically rational. Success for other reasons does not count.
“Epistemically rational” = correctly using observation and reasoning to arrive at true beliefs, and making the decisions and actions recommended by those beliefs.
“Irrational” = a privative concept, expressing not merely an absence of rationality, but an absence where presence is seen as having been possible.
How widely or narrowly you draw the line around “irrational” depends on how much of a counterfactual difference you are imagining being possible. Draw it widely enough, and sandstone is irrational for being so easily eroded by the wind. Narrowly enough, and everyone is perfectly rational all the time, in the same way that the Pentium III with the FDIV bug worked flawlessly. Somewhere in between there is a reasonable place to draw that line, but arguing over where to draw it is an argument about what to call things, not an argument about what properties those things have.
For the avoidance of doubt: I will happily agree that, all else being equal, being autistic is generally a disadvantage, and that this disadvantage is a matter of cognitive deficiencies and not only of (e.g.) prejudice on the part of others. I just don’t think “irrationality” is at all a good way to describe that disadvantage.
I am unconvinced by the broadest versions of the “rationality = winning” thesis, for reasons I’ve mentioned to alienist elsewhere in this thread. The very broadest version (“rationality = anything conducive to winning”) would make, e.g., shortness or heart disease kinds of irrationality. A more reasonable intermediate version (“rationality = any features of one’s cognition conducive to winning”) still seems to me overbroad; it means that e.g. one person can be deemed more rational than another simply because ten years ago they happened to learn a particular language, or because they have a better (or worse) ear for music.
I think your observation that epilepsy would be deemed a variety of irrationality by the definition you’re using is actually a handy reductio ad absurdum. Do you really want to define things so that epilepsy is a variety of irrationality?
For the avoidance of doubt: I will happily agree that, all else being equal, being autistic is generally a disadvantage, and that this disadvantage is a matter of cognitive deficiencies and not only of (e.g.) prejudice on the part of others. I just don’t think “irrationality” is at all a good way to describe that disadvantage.
I propose a few ways of using these words.
“Instrumentally rational” = successful on account of being epistemically rational. Success for other reasons does not count.
“Epistemically rational” = correctly using observation and reasoning to arrive at true beliefs, and making the decisions and actions recommended by those beliefs.
“Irrational” = a privative concept, expressing not merely an absence of rationality, but an absence where presence is seen as having been possible.
How widely or narrowly you draw the line around “irrational” depends on how much of a counterfactual difference you are imagining being possible. Draw it widely enough, and sandstone is irrational for being so easily eroded by the wind. Narrowly enough, and everyone is perfectly rational all the time, in the same way that the Pentium III with the FDIV bug worked flawlessly. Somewhere in between there is a reasonable place to draw that line, but arguing over where to draw it is an argument about what to call things, not an argument about what properties those things have.
I agree.