What’s the difference between ‘public intellectualism’ and being unusually willing to talk about stuff in public?

In the last year I’ve had a selection of requests from the media to talk on an eclectic range of issues: contemporary sexual culture, the quantified self, dystopic social change, the limits of liberal tolerance and hipster hatred. I’m fairly confident in dealing with the media and I enjoy the challenge of condensing ideas in the way necessary to communicate them effectively. However apart from a couple of occasions where people asked me to talk about open access and scholarly publishing, all these interactions have been concerned with asexuality. This is a subject I obviously do know a lot about and have felt confident discussing because I don’t doubt that I have genuine authority to speak: I’ve conducted one of the largest empirical studies, I’ve written widely about it and I’d like to think I’ve become reasonably effective at contributing to asexual visibility. I don’t say this to boast but only to illustrate that on this topic, any reservations I have about engaging with the media are entirely extrinsic to the subject. In terms of stuff I’ve been asked about recently, I’d actually really like to have said ‘yes’ in almost every case but I lack confidence in bringing any genuine expertise to the issue in questions.

However I also wonder if my notion of ‘genuine expertise’ is rather restrictive, suggesting as it does that the category of ‘public intellectual’ amounts to little more than someone unusually willing to speak in public on a range of topics far beyond those they have academic warrant to do so on. I have no qualms whatsoever about expressing my ideas on any subject when it’s on my blog but this feels different – it’s obviously not private but it’s also not public in the same way as speaking to a journalist writing an article for a national paper is. Perhaps if academics aren’t willing to speak beyond the range of their research topics then ‘public intellectuals’ come to be replaced by ‘social commentators’ who have no such qualms and, in many cases, lack the genuine expertise the former group has in a certain set of topics. Maybe it’s a case of primary and secondary knowledge? So I should feel uncomfortable with speaking on issues where I have no real academic grounding but should be willing to speak on those where I have a familiarity with the academic literature even if I haven’t undertaken research myself.

Or maybe I do want to be one of the ‘social commentators’ I just invoked so derisively and that my problem here is not with ‘public intellectualism’ but is rather with my commitment to ‘being an academic’.