The major reason for a nation to have a written constitution is to

The major reason for a nation to have a written constitutuion is to define the nature of the government's powers and processes

Ifeel like this means that we shouldn't just live for ourselves.also, we should respect others as well as people around us. it reveals that everyone should have equalized freedom, no matter their differences: races, cultures, skin color, etc,. we all deserve the same privileges.