Final answer:
Adolescence is a developmental phase where the focus is primarily on identity formation, which includes the development of personal identity and a struggle to establish autonomy while facing cognitive and psychosocial changes.
Step-by-step explanation:
The philosophical and developmental views of figures like Plato, Aristotle, and Saint Augustine on adolescence are not as explicitly classified as in modern psychological theories, such as those proposed by Erikson. However, when considering the period of adolescence, it is most accurate to say that these philosophers and subsequent psychological theories both align with the notion that this stage of life focuses on identity formation. This is the period where adolescents explore and refine questions like "Who am I?" and "Who do I want to be?" leading to the development of a stronger sense of personal identity. This stage can also include tensions between independence from parents and remaining connected, as well as cognitive development that mirrors adults in many basic thinking abilities but continues to grow in areas like insight and judgment.