‘Using the purity foundation’ =/= ‘Unable to think about it rationally and genuinely consider both benefits and costs.’
The purity foundation involves specific patterns of thought & feeling including the emotion of disgust and modeling the world in terms of purity and contamination, or elevation and degradation. People can be absolutist and unwilling to consider tradeoffs for moral views that come from any of the foundations (including harm/care, e.g. not wanting to torture a child no matter how big the benefit).
Liberals argue in favor of comprehensive intervention and regulation in nearly all areas of human life, but in contrast, people’s sexual behavior is supposed to be a subject of complete laissez-faire.
This is a wild exaggeration. There are large domains of life where liberals favor a large amount of freedom. See the 1st amendment, for instance. The standard distinction puts liberals higher on social liberty but lower on economic liberty; Haidt has used the term “lifestyle liberty” to describe the kind of liberty that liberals support. Liberals are relatively consistently opposed to legal restrictions on self-expression, for example, and they generally have social norms encouraging it (with some exceptions where it runs afoul of other norms).
The only plausible explanation I see here is that, just like everyone else in the human history, liberals base their sexual norms on a sacredness foundation
I don’t see a very plausible story of how the purity pattern of thinking would form the basis for norms of sexual permissiveness (maybe you could fill in some of the details?). The simplest explanation that I see is that sexual restrictions became tagged, in liberals’ minds (and in liberal culture) as traditionalist/oppressive/sexist/bad. (Because a lot of sexual restrictions did fit that pattern.) So, by pattern matching, now any proposed sexual restriction sounds bad, like something they support and we oppose. There are various particular psychological and cultural mechanisms that contributed to making this stick. For instance, it probably helped that sex can fit within the social/lifestyle/self-expressive category where liberals tend to be more laissez-faire. And it helps that they (the people who want to restrict human sexuality based on their retrograde puritanism) continue to exist (rather prominently, in many liberals’ minds), because that makes it easy to associate proposed sexual restrictions with them and to be suspicious of people who propose such restrictions.
‘Using the purity foundation’ =/= ‘Unable to think about it rationally and genuinely consider both benefits and costs.’
The purity foundation involves specific patterns of thought & feeling including the emotion of disgust and modeling the world in terms of purity and contamination, or elevation and degradation. People can be absolutist and unwilling to consider tradeoffs for moral views that come from any of the foundations (including harm/care, e.g. not wanting to torture a child no matter how big the benefit).
This is a wild exaggeration. There are large domains of life where liberals favor a large amount of freedom. See the 1st amendment, for instance. The standard distinction puts liberals higher on social liberty but lower on economic liberty; Haidt has used the term “lifestyle liberty” to describe the kind of liberty that liberals support. Liberals are relatively consistently opposed to legal restrictions on self-expression, for example, and they generally have social norms encouraging it (with some exceptions where it runs afoul of other norms).
I don’t see a very plausible story of how the purity pattern of thinking would form the basis for norms of sexual permissiveness (maybe you could fill in some of the details?). The simplest explanation that I see is that sexual restrictions became tagged, in liberals’ minds (and in liberal culture) as traditionalist/oppressive/sexist/bad. (Because a lot of sexual restrictions did fit that pattern.) So, by pattern matching, now any proposed sexual restriction sounds bad, like something they support and we oppose. There are various particular psychological and cultural mechanisms that contributed to making this stick. For instance, it probably helped that sex can fit within the social/lifestyle/self-expressive category where liberals tend to be more laissez-faire. And it helps that they (the people who want to restrict human sexuality based on their retrograde puritanism) continue to exist (rather prominently, in many liberals’ minds), because that makes it easy to associate proposed sexual restrictions with them and to be suspicious of people who propose such restrictions.