I went to a conference on the social life of things, which was organised by a man called Arjun Appadurai and I thought for that I ought to say something about the Varna Cemetery and the earliest gold in the world. That was a cemetery in Bulgaria where the new radiocarbon chronology established that the gold found there was about 4,000 BC, and still the gold, the earliest gold know anywhere in the world and you find it in the graves and you find it in bracelets and nose plugs and so on, and I began to ask myself, how would you show that the gold was valuable? We all think of gold as valuable, but how do we know it was valuable to them? Because I realised I could say this is the emergence of a concept of value, which in a way could be a, analogous to the emergence of a concept to weight. Something new coming in to the world. But before you can say it is worth so much, you have to have the very notion of value. What is it for there to be a valuable material? And this gold seemed to be one of the earliest examples you can show where something was clearly being valued. You might say the same with polished stone axes in the Neolithic, but just a few - or maybe amber beads also. So - but how would you show? We can see gold ought to be valuable because we all think of gold being intrinsically valuable. But when you think about it, gold is intrinsically valuable because all humans agree that it is valuable, otherwise it wouldn't be. And it’s what the philosopher John Searle calls an institutional fact, and I began to be interested in the way societies agree on certain facts that are only facts because they are agreed. Like, you know, the, the, the, the pound in your pocket is valuable or the whole business of money is just an agreed codified system. And in the case of the archaeology of gold the fact that it was being used in contact to the skin, for earrings and so on and bangles, was one indicator, and also some objects that appeared to be penis sheaths of gold in the graves and that would be the same line of thinking. But also there was one stone axe, in one of the graves that had been covered with gold foil and though it wasn't completely preserved, one presumes that the whole axe had been covered with foil to make it look like gold. Well, if you think about it that presumably implies that a gold axe would be more special and more valuable than the stone axe that they'd covered with this foil. And so I found that an interesting set of ideas to try and develop and I wrote about that for this conference on the social life of things, and it set me thinking much more about the emergence of really fundamental concepts, like the concept of value. And I see this within a framework of cognitive archaeology, think one's really getting at some of the issues of, how does a weight system ever come about or how does the concept of value come to emerge in different societies? Because of course in Meso- America, jade or feathers were considered even more valuable than gold, though gold was valued there. So, I, I thought that was an interesting set of ideas and I now have the feeling that it is possible to develop a kind of cognitive archaeology but it's not easy to do. One has to work out how it is that different societies, create difference of conventions for a living, formulate different institutional facts, formulate different value systems and this obviously relates to the archaeology of religion, although not directly, we're in the same sort of subject area. So I got rather excited about this idea and I had a very bright research student who was doing a PhD, Lambros Malafouris and he completed his PhD, developing this idea of material engagement and using it in relation to the Mycenaean civilisation and talking about what a sword would mean and how important it was, and there was an early PhD dissertation by Paul Traherne in Cambridge, who wasn't particularly a student of mine, but he wrote a wonderful dissertation on the theme of the warrior’s beauty in the European bronze and iron ages, where it is the case that metal weapons become very prominent and also people riding horses in the first millennium BC and so on, and he showed how all these things fitted together and those societies had developed a way of seeing certain things as right, and ultimately beautiful and appropriate and that involved the use of swords and so on. So, all kinds of different ideas seem very possible and positive in the material engagement direction.