I read quite a bit about Stoicism - an ancient Greek school of philosophy founded at Athens by Zeno of Citium. The school taught that virtue, the highest good, is based on knowledge; the wise live in harmony with the divine Reason (also identified with Fate and Providence) that governs nature, and are indifferent to the vicissitudes of fortune and to pleasure and pain.

The Stoics elaborated a detailed taxonomy of virtue, dividing virtue into four main types: wisdom, justice, courage, and moderation.

Many may not view this as “spiritual” as it does not address “spirits” but rather personal empowerment.