During the negotiation of the constitution there were people for it and there were those against it. People who felt that the states should retain a major amount of power were called Anti-federalist. The others who believed in a strong central government were called Federalist. One famous Federalist is referred to as "the father of the constitution" who is called James Madison and in order to convince those to support the constitution he, among others, wrote up different papers that gave reasons as to why the constitution should be ratified called the Federalist papers. In the tenth paper Madison writes about factions. He believes that factions will forever separate the country from becoming a union and that these factions are brought up by the passion each one shares. Madison feels that in order to stop these factions one most control the effects each plays on society and does not believe to endorse the method to get rid of it in order for a democracy to work. .
There were two ways that Madison felt it was possible to get rid of factions. These methods were to take away the causes and the other would be to control its effects. In order to take away the causes one must start by destroying the liberty that's essential to its existence and the other would be to give them all the same opinions, same passions, and same interests. To control the effects one must have the power to make sure that these factions with similar passions will not have a majority in society but a minority. Between these two Madison felt that to take away liberty and to destroy these passions was unlikely and nearly impossible. To control the effects would have a far better chance of success and not to take away those liberties which citizens pride themselves on. .
Now one can see what method Madison has decided, but not why. The decision made in favor of not endorsing the method to rid of passion was mostly because citizens do have an unalienable right to differences in passions.