So in Psychology Today this guy Alain de Botton says something that ought to creep out a lot of victims of sexual violence and comfort or even delight any number of perpetrators.

Involuntary physiological reactions such as the wetness of a vagina and the stiffness of a penis are emotionally so satisfying (which means, simultaneously, so erotic) because they signal a kind of approval that lies utterly beyond rational manipulation. Erections and lubrication simply cannot be effected by willpower and are therefore particularly true and honest indices of interest. In a world in which fake enthusiasms are rife, in which it is often hard to tell whether people really like us or whether they are being kind to us merely out of a sense of duty, the wet vagina and the stiff penis function as unambiguous agents of sincerity.

Source: Psychology Today (naturally)

So... What's wrong with this picture?

Two things: First, it's totally wrong that an erection (or a wet vulva) can only mean arousal, let alone that they are "particularly true and honest" indicators.  As pretty much every man who's woken up with a full bladder can tell you.  

But second, as too many victims and perpetrators(!) of sexual violence can tell you, victims of sexual violence can develop or be made to develop(!) erections (or vaginal lubrication) and even ejaculations!

See for instance this post from Living Well, an Australian site for recovering male victims of sexual violence (my italics)

People who sexually abuse boys and men often use their knowledge about male bodies to deliberately cause an erection and/or ejaculate to occur. They do this because they know it is extremely confusing and embarrassing. They might also do it to try and convince both the person being abused and themselves that what is happening is not really abuse. Whatever the reasons, ultimately they know that if the boy or man was aroused, they might be less likely to tell anyone about the abuse due to feelings of shame and embarrassment.

Source: Living Well: Sexual Assault and Arousal

Or see also this from (a more woman-focused but still appropriate for men) survivor-support site the Pandora Project (my italics.)

A sexual response or orgasm in the course of sexual assault is often the best-kept and most deeply shameful secret of many survivors. If you are such a survivor, it’s essential that you know that sexual response in sexual assault is extremely common, well-documented and nothing for you to be ashamed of.

Source: Pandora Project: Sexual Arousal & Sexual Assault

This is consistent with what a number of sources have to say about the way perpetrators (relatives, fellow prisoners, priests and scout leaders, and of course aggressive hetero date-rapists) manipulate their victims into a) submission, b) co-operation, c) deep and abiding shame, and especially d) silence.  

Oh, and sometimes?  e) ignorance and long-term misunderstanding.

For instance if you've ever been told "You're hard, that means you want this," or "Look at you, you were soaking wet, you were loving it?"  When you hadn't really been loving it but couldn't figure your way around their point about your "particularly true and honest indices of interest?"  You might want to sit down and talk with somebody who can help you figure out what was (or is) going on.

Lest you think de Botton's particularly insidious form of gaslighting applies only to victims of sexual violence, it's important to get that some perpetrators really believe it themselves!

Check this out, also from that Pandora Project article

And it isn’t just about you and the way your body responded either. It may also have been one of the repertoire of dirty tricks rapists use to get their victims to feel responsible. Diana Russell writes that “Some rapists think they’re lovers” and tells us:

(These rapists) think that if a woman is stimulated in ‘just the right way’ she will enjoy it. The conquest may seem more important if the rapist believes he has turned the woman on physically, particularly if it is against her will. Getting the victim to respond physically may also alleviate the rapist’s guilt feelings.

This, incidentally, was one of the things that completely threw me for a loop about a year ago when it first started to soak in that an awful lot of my personal assumptions about sexual behavior growing up had been learned, some of it from a very early age, by people who themselves had been sometimes radically abused and by others who were themselves active abusers.  Thrown me for enough of a loop that while I'm still pretty sure I've always been a considerate or at least very well-intentioned sex partner I feel obliged to question whole constellations of assumptions I've made in the past.  One thing for sure, for me, personally, is that "at least I'm not like those guys" and even sometimes "at least I'm not like those gals" no longer feels all that reassuring.

Summary: if you would have found de Botton's claims  reassuring, or even just reasonable, take a little time to re-think some of those assumptions.