This book focuses on the ideas to embed nuclear physics in the larger context of hadronic physics by stressing and deepening its widening overlap with particle, astroparticle and condensed matter physics and to emphasize the unity of the two facets not only of nuclear, but of the whole physics; the theoretical and the experimental ones. Counteracting the ominous trend of enlarging the gap between the two, the danger being of depriving experimental physics of ideas promoting experiments and of transforming theoretical physics into metaphysics. The reader will find modern conceptions on nuclear structure, how atomic nuclei are probed through the scattering of high energy electrons and how they interact when accelerated at ultra-relativistic energies. The item connects to the quest for the quark-gluon plasma, perhaps the central theme of the contemporary hadronic physics, whose unraveling requires a vast and profound knowledge of both nuclear and particle physics, in particular QCD.