I pondered for some time about whether to make the review of this book through the lens of when it came out, or whether to compare it to the books of nowadays, and I think the latter is more fair, because if someone came looking for an introduction to the sciences they should see reflected in the rating the real experience of reading it now.
This is the reason I could not rate it higher, and I think I was even a bit benevolent. The reality is that this is an old book, and a lot of things can change over time, especially in science. This is also reflected in the technologies of writing at the time: the book is very dense, and could benefit from more illustrations and resources to help the reader navigate through it more fluently, and keep track or visualize everything better.
Another issue I had was with the development of chapters. At the beginning of the chapter it is easy to keep track of the topic, but as it continues and the author links more and more ideas it becomes a bit fatiguing to follow it. But to be fair, it is a respectable effort to condense all the most important findings of a field in a single chapter, and to relate them in such a way.
Also, as the title of the book suggests, it is supposed to serve as an introduction, so I guess the target audience would be someone without much prior knowledge about science in general, but I have to say it is though to go through, even with a bit of knowledge beforehand. I would probably not recommend it to someone wanting to dive into the topic, as I think it would probably be a challenge and discourage them.
But I think I am being too critical of the book, there are also many points which I quite enjoyed about it. You can really tell how much the author is fascinated by science, and he does transmit it by the way it is written, it really makes you realize how far we've come.