Whereas On Time, Causality, and the Block Universe began with the premise of a block universe, this book first justifies it by showing eternalism to be the only non-contradictory model of time. However, this book better differentiates space-time from the underlying block universe, which it posits to be an isotropic continuum whose content is responsible for our notions of space and time. The fact that time is relative to an observer's frame of reference in modern physics forces a differentiation between the classical conception of a block universe, which implies eternalism and so absolute time, and any modern block universe model.
The subject of causality is further analysed to show that the principle of causality is not simply a matter of a subjective selection of scale, but also of an identification of the causal agent, which may be physical or non-physical at any scale. This corresponds very closely with our everyday cognition of causality, and yet breaks no laws of physics. Removing any fundamentality attributed to causality does not affect our mathematics, but it has profound implications for the interpretation of that mathematics and for scientific explanation in general. This recognition actually helps physics by removing an axiom of experience, and it dismisses philosophical issues surrounding mind-body dualism as either possibikity is a viable explanation in given circumstances.
The book looks deeply at the evident arrow of time usually attributed to the second law of thermodynamics. The universe is not an idealised gas and the premise that change always tends to disorganisation misrepresents reality to some extent. If it was so then we would have no macroscopic structure, no notion of identity, and no capacity to store correlations or algorithmically process them. The emergence of conscious entities in a block universe is clearly a core concept for the model to be viable, and so it is given a more in-depth treatment in this book.
The book takes a deep dive into quantum mechanics, special relativity, and cosmology, particularly exploring interpretations compatible with a block universe model.
A chapter is devoted to the thoughts of selected physicists and philosophers, both old and new, including Einstein, McTaggart, Minkowski, Bergson, Rovelli, and Barbour.