Club of Rome Quartet

There are some incredibly smart things Brunner does in this novel. The story is told from the perspective of a world of intelligent aliens as they reach out to discover the universe in which they live. They have to do that in ways that are very different from our own history in details (for example, they live under water where access to the night sky is limited, which puts a crimp in early astronomy), but very similar in the abstract. The similarities arise for the simple reason that the universe in which they live is THE universe. The message here is deep & subtle & important: reality is what it is, & no matter what kind of body you have, no matter what specific environmental niche you occupy, if you are smart enough to wonder about the world you live in, & clever enough to discover ways to ask your questions well, you will discover the same immutable facts about the nature of things. Brunner shows this without ever giving a lecture or explicitly making the point. It's a story telling tour de force that really puts the science solidly in the center of science fiction.