We cannot achieve fulfillment simply by aiming for it, Aristotle taught; instead, we must cultivate traits of character (which he called virtues) that will lead us to behave automatically in a way that contributes to our success.
Aristotle also writes about vices. For every virtue there are usually two vices – one representing too much and one too little of the virtue in question. The vices of fearfulness and foolhardiness, for example, represent an imbalance of courage. Those who pursue excellence will cultivate a reasonable and measured way of life, the famous doctrine of the “golden mean.”