In The Republic Plato described the four key virtues of a good person: prudence, temperance, justice, and fortitude. It is not surprising that these virtues have a huge part to play in the practice of sustainability.

Temperance

Temperance means self-restraint, moderation and discretion. In terms of sustainability, Temperance is probably the most obvious of the virtues. The virtue of temperance is required to live within the sustainable limits of the Earth. Profligacy, the opposite of temperance, not only leads to environmental degradation, it is also leads to ill-being. Temperance speaks to the notion of thriving with moderate but sufficient means.

Prudence

Prudence is another word for wisdom, especially in knowing what is the right thing to do in a given situation or circumstance. It is a type of discernment or foresight for making good decisions considering all possible outcomes. Prudence helps create sustainability because it maintains the attitudes of prevention, conservation, caring and mitigation.

Fortitude

Fortitude is courage, but it is also about strength, resilience and endurance. Something that is resilient will last longer, and when it lasts indefinitely that is the very definition of sustainability. Sustainability involves not only knowing what is right but also the ability to stick at it, so being sustainable, on an individual level, requires courage, determination and heart.

Justice

Justice is the other half of wisdom (prudence being the first half). It is the middle point between selfishness and selflessness, in other words the balance between having more and having less than one’s fair share. Justice also speaks to doing the right thing not just for ourselves, but for the common good and for the environment as well. For sustainability to happen, justice is about everyone taking responsibility for it. Sustainability cannot be left to a few, while the rest are profligate.

A moral compass

Further to Plato, the Roman Emperor and Stoic philosopher, Marcus Aurelius, views the cardinal virtues as the “goods” that a person should establish in one’s own mind, as opposed to “wealth or things which conduce to luxury or prestige.” This statement sums up the thinking behind sustainability. Right ways of thinking and acting are the real wealth (the intrinsic “goods”) much more so than extrinsic consolations such material wealth, prestige and luxury.