The central features and puzzles of particle physics will be reviewed, including the recent discovery of a Higgs boson at the CERN Large Hadron Collider. The associated criterion of Naturalness will be introduced as the dominant (but not infallible) organizing principle behind many searches for particle physics beyond the Standard Model. The herculean task of testing naturalness will be summarized, especially the fluid interplay between deep theoretical ideas, such as Supersymmetry and Compositeness, and experimental strategies and findings at the LHC.