I have been reading Plato and re-reading Nietzsche and both of them discuss Virtue without saying what it is. In Thus Spake Zarathustra Virtue seems to come in flavours where you have to pick one or they tear you apart. Virtue by Socrates is something handed down from the Gods but none of them explain what it means to be virtous or what Virtue is. I'm not a philosopher so I'm probably missing a lot.
Virtue is a concept with a long history in philosophical thought, and its definition can vary significantly depending on the philosopher or tradition being referenced. However, at a broad level, virtue is often understood as a character trait or quality deemed to be morally good or desirable.
In the context of Plato and the ancient Greeks, virtue (also known by its Greek term "arete") referred generally to "excellence" or "living up to one's potential." Plato often discussed virtue in relation to the concept of the "good life" or "eudaimonia," suggesting that virtuous living was a key component of human flourishing. In this context, virtues are seen as innate potentialities that can be cultivated and developed to achieve this state of flourishing.
For example, in his dialogue "Meno," Plato discusses four cardinal virtues: wisdom, courage, temperance, and justice. These virtues, according to Plato, are necessary for a well-ordered soul and a well-ordered society.
Nietzsche, however, had a very different perspective on virtue. He was critical of traditional moral systems, including those that valued virtues such as humility, altruism, and selflessness. Instead, Nietzsche championed virtues that he believed were life-affirming and that celebrated the individual's will to power. In this sense, Nietzsche's virtues may seem more like "flavors," as you put it, because they can vary greatly depending on the individual and their own unique will to power.
Nietzsche was kinda critical of the idea that virtues are handed down from the gods or any higher authority. Instead, he believed that virtues (and values in general) are created by individuals and communities, and that these values can and should be re-evaluated and re-created over time.
The easiest way to define virtue (in the abstract) is to see virtue as an ideal of action: one does what is good, right, proper, or correct within a context. As such, virtue is both cognitive and performative. One has to know what the correct course of action is and how to do it, and then one has to follow through. The Ancient Greeks often talked about virtue in terms of athletics, because it's a concrete representation. To throw a discuss or a javelin one has to learn the technique, train the body and the mind into the correct form, and then put it all together at the games (or on the battlefield). But every other human activity — from love to poetics to politics to... — also has its own virtue ideal.
Christianity took this active notion of virtue and made it passive; Christian virtues are almost all 'shalt nots'. I suspect this is because Christianity took the view that sin is fleshly, and we only need to refrain from fleshly indulgence to guarantee the already-sanctified soul. However that may be, Nietzsche took exception to the restrictiveness of Christian 'morals', which he saw as a hypocritical form of social control. Virtue is still an ideal of action for him, but it is an ideal that each must discover, not something that can be handed down through doctrine. Nietzsche's over-man is a representation of a person who has become the source and author of his own virtue.