Lee Smolin has an interesting article on Einstein's legacy where he cites the moral quality of Einstein's thinking. I found this especially thought provoking:

In the transition from Aristotle to Newton to special relativity, that structure changed, but in each case the structure remained fixed. We and everything that we observe live in a space-time, with fixed and unchanging properties. That is the stage on which we play, but nothing we do or could do affects the structure of space and time themselves.

General relativity is not about adding to those structures. It is not even about substituting those structures for a list of possible new structures. It rejects the whole idea that space and time are fixed at all. Instead, in general relativity the properties of space and time evolve dynamically in interaction with everything they contain. Furthermore, the essence of space and time now are just a set of relationships between events that take place in the history of the world. It is sufficient, it turns out, to speak only of two kinds of relationships: how events are related to each other causally (the order in which they unfold) and how many events are contained within a given interval of time, measured by a standard clock (how quickly they unfold relative to each other).

Thus, in general relativity there is no fixed framework, no stage on which the world plays itself out. There is only an evolving network of relationships, making up the history of space, time, and matter. All the previous theories described space and time as fixed backgrounds on which things happen. The point of general relativity is that there is no background.

This point is subtle and elusive.

It's a point that helped me to better understand the mechanics behind the Inflation Theory of the early universe.  ¶ 7:59 AM