Abraham Pais was a Dutch-born American physicist and colleague of Einstein who wrote Subtle Is the Lord: The Science and the Life of Albert Einstein.

Quotes by Abraham Pais in Time One

[T]he origin of inertia is and remains the most obscure subject in the theory of particles and fields.

Today an individual galaxy is considered as a local disturbance of a distribution which is indeed isotropic and homogeneous, to a degree which itself demands explanation. Einstein had no such physical grounds for assuming these two properties ….

That fellow Einstein suits his convenience. Every year he retracts what he wrote the year before.

Einstein and Bohr, the two leading authorities of the day, were locked in conflict (the word conflict was used by Einstein himself). To take sides meant choosing between the two most revered physicists.

Einstein never ceased to ponder the meaning of the quantum theory.