The Moon is a Harsh Mistress has become one of my favorite books and I really liked being able to talk about it with a group of friends because of all the great philosophical points in it.  Heinlein was really ahead of his time, and ahead of now, with all the topics he covers.  Some of the tech is obviously dated, but it seems very plausible despite that, and given it was written in the 60’s it is absolutely phenomenal.

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