Which axial age thinker focused primarily on attaining personal contentment and spiritual growth, rather than achieving social and political order?

Out of the axial age thinkers, the one that focused on attaining personal contentment and spiritual growth was Siddhartha or the Buddha.

The axial age is a term invented by the German philosopher Karl Jaspers to describe a period of time when the intellectual, philosophical and religious system that came to shape human society and culture emerged. This happened around 800 BCE to 200 BCE and included the ancient Greek philosophers, Indian metaphysicians and logicians, Persian Zoroastrianism, the Hebrew Prophets and the "Hundred Schools" of ancient China.