From one of my early undergraduate courses, I remember reading a brilliant argument about the nature of the universe that described the nature of temporality - the argument was around a statement of the form:
"if I had gone out for my walk this morning wearing a hat, it would have meant the entire universe would have been different than it is."
The line of reasoning from there was fascinating to me - he set out the argument that the antecedent events that necessitated him deciding to wear a hat extended backwards in time to the origin of everything. It was, in many senses, like the inverse of the Butterfly Effect.
The problem I'm having is that I can't remember the philosopher or the work that it was in. And I'd really like to go back and re-read it. I keep thinking it was G.E. Moore, but I can't find any reference to any sort of discussion like that in his work. I have Googled everything I can think of, and even went so far as to email the professor who I thought taught that class (who gave me an absolutely brilliant response that I'll have to blog about soon enough, even though he wasn't the person who taught the class and didn't know the actual reference).
Can anybody point me to the appropriate philosopher?