As stated in the scenario, George donates to charity but still provides a comfortable life for his family. He has found a balance between the competing virtues of giving to the less fortunate while also ensuring that he provides for his family. This is an illustration of:

principle of the golden mean

Explanation:

The doctrine of the Golden Mean represents a  scale to determines what is virtuous. The principle of golden mean was first found in the writings of Aristotle who believed that good life was based on cultivating ability to reason.  Aristotle concluded that being morally good required striking a two-vice balance.

It is based on the notion of moderation that is the search for a balance between two extremes. As per the question, George donates to charity but still provides a comfortable life for his family and his action reflects to satisfy the principle of golden means.