Frankly, this was a huge disappointment. I think that one aim of science fiction is to develop new ideas and to flesh out familiar ideas by exploring them in unfamiliar settings, and in this respect the book certainly succeeds: the perils of ethnocentrism in interplanetary (and interspecies) communication, polyamory and new understandings of partnership and marriage, Fair Witnesses that report events exactly as they occurred to their senses (without giving their interpretations), and the means of contributing to a better world - this book has great ideas and motives in abundance.

I somewhat liked were to plot went towards the end. Everything became way more structured and I was more able to grasp what was going on in earlier parts. However, I think the story would have worked better as a short story (I read that the most popular version of the book is heavily abridged; I doubt that I would want to read the intended version). There are many scenes that drag on and on and of which I'm really not sure what their function in the greater narrative was. Is this supposed to be funny? This really escaped me to be honest.

Unfortunately, what is worse is that the book feels so dated that it was very difficult for me to actually like it at all. I guess you could see past the occasional faux pas (Indians and black people as being closer to Cannibalism? the Muslim as being the weirdest among the weird religious people?), but old man's jokes about the relationship of men and women on about every single page? That was really too much for me. Heinlein doesn't seem to think that a woman has any existence independently of men; in fact, most relationships in the book were more similar to master-slave-relations rather than a relation between autonomous persons. At one point of the book a main protagonist says something among the lines of "In matters of taste you should be able to look past your education and upbringing granting other people their way of living", but this certainly doesn't apply to moral matters of justice and equality. I see that today there is some headwind against unconditionally accepting Heinlein's status among one of the three or four greats. But maybe people should be even more outspoken about this.