That little quip from Hume has influenced my thinking so much Im happy to see it again

I agree, I love him and he has been a very influential person in my life. I started reading him from a very young age in my own language because his works in English were too difficult for me at the time. It is always nice to see someone mention him.

FWIW I do not think he used the "pig with dragon head" example, it just came to my mind, but he did use an example similar to it when he was talking about creativity and the combining of ideas where there was a lack of impression (i.e. we have not actually seen one anywhere [yet we can imagine it]).