Teller was a psychopath, pure and simple. He was also pretty smart which made him even more dangerous, I reguard him as one of the few humans whose decisions and actions could have wiped us all out as a species.

Under what definition of smart a smart human works to create the means to end the species?

An interesting question which I find that would take me too long to answer, the shortest answer that I can come up is that I’m writing this comment from a device called a smart-phone whose battery is not replaceable, meaning that in maximum two years or so it will be in a dumpster together with other thousands, even hundreds of thousands of similar smart-phones, with all the nice rare and toxical metals of which they are composed slowly making their way into the ground and into our water-sources. What I mean to say is that we ourselves as a species can be seen as being pretty smart from a certain point of view (we went to the Moon, we designed and currently make electronic devices that can fit in our pockets and with each we can have conversations with total strangers from half a world away) but at the same time we do our best in order to destroy the livable habitat from the unique planet we’ve managed to populate so far. As such, people like Teller are the perfect representatives of this side of ours as a species: smart but self-destructive.