Permitting the organization of different mutually exclusive groups to represent different political perspectives, and the creation of adequate mechanisms to allow them to compete for ruling positions in government.
The toleration or provision for political pluralism is simply a recognition that in human intellectual and behavioural nature there will always be conflicting political ideas. The accommodation of this fact in the legal structure of government is a bulwark in the defence of individual freedom of speech.
A multi-party system institutionalizes differences among perspectives keeping dead ideas alive and only slowly adding on new ones.
It limits free dialogue by defining the admissible concerns and questions.
Because parties are competitive, the system cannot create consensus; rather it develops a more or less acquiescent minority.