Can you recommend any books, articles, essays, online tutorials/courses, etc that would be interesting and useful for an epidemiologist/biostatistician to learn about the philosophy of causation/causal inference?

I know quite a bit about actually doing causal inference from an epi and biostats framework, but I would like to learn something about the philosophy which underlies and motivates this work. For example, it's my understanding that Hume first talked about ideas that could be interpreted as counterfactuals. 

I have basically no training or experience with philosophy, so I need something relatively introductory to start of with, but I would also be interested in recommendations for more complex but important/foundational texts/authors (but please indicate that they are not introductory). 

I hope this isn't too off-topic for cross-validated, but I'm hoping that some of you will have been in the same boat as me before and able to share your favorite resources.