Jacques Laforest provides an introduction to gerontology viewed as an interdisciplinary field of study and reflection on old age. Old age is defined from a developmental perspective as two opposite yet complementary processes: those of decline and growth. The final stage of life is marked by an existential crisis of one's identity, autonomy and belonging. Researchers and specialists from all disciplines are invited to contribute towards an understanding and a resolution of this crisis. The purpose of this publication is to initiate the process of integrating knowledge and reflections on gerontology. This goal is achieved.