Rob Clifton was one of the most brilliant and productive researchers in the foundations and philosophy of quantum theory; he died tragically at the age of 38. Jeremy Butterfield and Hans Halvorson present fourteen of his finest papers, all of which combine exciting philosophical discussion with rigorous mathematical results. Many of these papers break wholly new ground, either conceptually or technically. Others resolve a vague controversy into a precise technical problem, which is then solved; still others solve an open problem that had been in the air for some time. All of them show scientific and philosophical creativity of a high order, genuinely among the very best work in the field. The papers are grouped into four parts. First come four papers about the modal interpretation of quantum mechanics. Part II comprises three papers on the foundations of algebraic quantum field theory, with an emphasis on entanglement and nonlocality. The two papers in Part III concern the concept of a particle in relativistic quantum theories. One paper analyses localization; the other analyses the Unruh effect (Rindler quanta) using the algebraic approach to quantum theory. Finally, Part IV contains striking new results about such central issues as complementarity, Bohr's reply to the EPR argument, and no hidden variables theorems; and ends with a philosophical survey of the field of quantum information. The volume includes a full bibliography of Clifton's publications. "Quantum Entanglements" offers inspiration and substantial reward to graduates and professionals in the foundations of physics, with a background in philosophy, physics, or mathematics.