Moral codes serve as indicators of social solidarity because they represent the collective agreement that binds society together. For Durkheim, society exists as a moral community over and above the individual, and the ties that bind people exert pressure on individuals to conform to norms and expectations of the group.

The nature of moral codes reveals the type of solidarity in a society. In societies with mechanical solidarity, moral codes are strict and violations attract harsh punishment. This is because such societies are based on similarity of members and are not tolerant of differences. Any violation of codes is feared to result in the disintegration of the community, hence repressive laws prevent deviation from community norms.

In contrast, societies with organic solidarity have different moral codes. Modern societies based on heterogeneity and interdependence have restitutive laws that aim to repair or correct wrongs rather than punish. This reflects that organic solidarity celebrates individual differences and recognizes multiple roles.

Thus, by observing moral codes and behaviour patterns, we can identify the invisible social solidarities governing society. The prevailing social conditions can be deduced from moral codes, making them observable indicators of social solidarity.