The above question is comprised of several different terms. Those terms are: justice, civil society, and just society. All of these terms cross several disciplines including law and philosophy. Any easy way to start thinking about the term justice is to consider what is fair.
Many consider fairness as all opposing sides are equally heard and their conflicting viewpoints considered in making decisions, such as laws. The concept of fairness is tricky relative to justice because what is fair is not necessarily what is just. As such, just laws may be considered unfair to some and vice versa.
Just laws are necessary for a civil society, otherwise there would be anarchy. A convenient way to consider civil society is the collection of people and institutions that must function together in harmony in a given geographical area or a country. As such, the idea of a “civil society” will be different from country to country because the laws are different. Laws considered just in one country may be considered unjust in another.
Finally, the term just society can be thought of as a combination of the terms “justice” and “civil society.” A starting point for understanding and defining the term “just society” is one in which individuals and institutions function in harmony, and neither oppresses the other.
The philosopher Plato considers exactly the question of “what constitutes a just society” in his work The Republic. Below is further information about the terms justice, civil society, and just society, as well as a discussion about Plato.