The word adiaphora (plural: adiaphoron) is from the Greek and means “indifferent.” Originally developed as a concept by the Cynics and Stotics and means those things that are neither mala inse (eveil in themselves) nor are they buno in se (good in themselves). In modern Christian theology it has developed into the concept referring to those things in which no binding moral guidance has been given.
However, better or worse choices might still be made in matters that are adisphora. For example, the Apostle Paul said in 1 Cor. 7:35: “I say this for your own benefit, not to lay any restraint upon you, but to promote good order. . .” In short, Paul is not issuing a hard and fast moral ruling, but is rather suggesting a better course of action; one that will cause less disruption to the community.
For later Cynics and Stoics, matters of adiaphoron relate more to the base or animal natures of humans and less to human spiritual needs. For example what one eats to stay alive and healthy is generally a matter of spiritual indifference. However, it might be morally a better choice to eat lightly, to not be gluttonous, to not drink too much and to perhaps avoid meat. For the early Christians, Paul discussed this in Romans 14:2: “One person’s faith allows them to eat anything, but another, whose faith is weak, eats only vegetables.” The meat eater is not committing a sin, or a decided moral wrong, but rather has made a choice. The choice is neither a right nor wrong one; it is merely one that they have made for themselves and it might not be a good choice for anyone else.
What does the concept of adiaphora mean for such decisions and for the moral world in which these choices are made? It does not mean indifference in the sense that the choices make no difference, but rather that there is no morally absolute principle behind any particular choice.
Without direct moral instruction on any given point, the human must rely on their own spiritual and moral guidance. That is to say, they must depend on their “conscience”, on their own reasoning, knowledge and wisdom. Also they may rely on the generally accepted rules of their community for guidance in such matters as well.
Therefore matters that are adiaphoron are matters that the social contract; the society as a whole must deal with and provide direction and are also matters of personal conscience as well.