One of the interesting aspects in the study of atomic nuclei is the
strikingly regular behaviour many display in spite of being complex
quantum-mechanical systems, prompting the universal question of how regularity
emerges out of complexity. It is often conjectured that symmetries play a
pivotal role in our understanding of this emerging simplicity. But most
symmetries are likely to be broken, partial or both. Under such more realistic
conditions, does the concept of symmetry still provide a basis for our
understanding of regularity? I suggest that this requires the enlarged concepts
of partial and quasi dynamical symmetry.Comment: 5 pages, 5 figures, accepted for publication in Nuclear Physics New
