That is a question I am sometimes asked (alongside the incredibly irritating put down “you have too much time on your hands”). In truth, I rather like the "occupation", as it was described, of a guest one time on the BBC's "Newsnight" programme; he was introduced by the presenter Jeremy Paxman as, "A Thinker". So, I'm happy to be called "a thinker", safe in the knowledge that, as a self confessed solipsist, whether others think those thoughts are nonsense or not, is almost of no consequence to me (I say almost because I do enjoy developing, or indeed, demolishing, the thoughts of others, when that is deserved, of course). Anyway, today, I spent a good hour or more discussing the subject of “reality” with an old friend of mine, who is known as the “The Prof” (see pic above). As it happened, the Prof disagreed with my entire hypothesis on the subject of reality. And, in fact, although he has a string of academic qualifications including two doctorates (hence “The Prof”), covering both the hard and soft sciences, he definitely began to lose the argument. This, by the way, and in fairness to him, is inevitable once you accept that “reality” can ONLY exist in our individual heads – he tried to suggest that, sure, there was that reality in our heads, but there was another, “more real”, if not “the” real one which was absolute – I asked who, by name, might perceive that particular reality and, of course, the game was up, since any reality can only ever be perceived by an individual human (or other being), within their individual mind and therefore it remains necessarily subjective. He then played the "credentials" card, by challenging one of my references, in order to discredit it, which is an old trick. As it happens, I recalled that I'd certainly looked at the work of a Hilary Putnam who had written a book called “Reason, Truth & History” in 1981, covering an elegant concept called “Brain in A Vat”. The Prof immediately trashed this source, the writer being, in the Prof’s words “An American Sociologist quack". Indeed, he warned me that if I was going to quote "serious" philosophers, I should ensure they were just that. As it had been some time since I’d looked at the source, and since the Prof was so definitive in his dismissal of Putnam, I didn’t dispute it. In truth, I was actually slightly disappointed that my argument had been speciously undermined by a common, but slightly underhand technique. “Oh well”, I thought, quack or not, I still think his ideas are elegant. The Prof, incidentally, described Putnam's ideas as “ludicrous”. After the call, I checked out Hilary Putnam and his credentials (details above) and he’s definitely not a quack (as can be seen). I called the Prof back and protested. He laughed and confessed to a simple poker game ploy, which did almost work. In fairness, I then received a text from old Prof saying that Putnam had, in any event, tried to subsequently discredit the “Brain in a vat” theory. So, perhaps, one might conclude from this that I do have too much time on my hands, or, conversely, one might equally conclude that we should ALL spend more time, like me, thinking. Finally, I’ll sign off with the question which, I'm afraid, our call failed to resolve, which was: “what is more important, agriculture or football?”.Think about it, answers on a postcard….