It's the issue that is not discussed publicly, yet it cannot be ignored. To move on from the still-present national schism to national reconciliation requires a thorough investigation of an amnesty.
At the same time, every attempt to raise the issue rubs a raw political nerve, demonstrating splits in society.
In truth, it's time to take one step backwards from the amnesty issue, with a view to then taking several steps forward.
The immediate problem with raising the issue of an amnesty goes back just over a year. In one of the crudest and most ill-advised moves seen in Thai politics, the government of then-prime minister Yingluck Shinawatra pushed an amnesty bill into the House of Representatives.
It was clearly written with a single goal: To clear all legal charges facing ex-premier Thaksin Shinawatra so he could return to Thailand without the threat of having to account for alleged law-breaking during his time in office.
This crude objective was transparent; it was also designed to strip away all legal charges against ex-premier Abhisit Vejjajiva and his former deputy Suthep Thaugsuban. They were accused of murder during the crackdown they ordered against red shirts — Thaksin's supporters — in the 2010 street violence in Bangkok. Mr Abhisit and Mr Suthep, currently Phra Suthep, both stated they did not want an amnesty.
But at 3am in parliament, when the Democrat opposition had gone home, Ms Yingluck's parliamentary majority passed this odious bill. Public reaction to this bill and the detestable legislative tactic was instantaneous, bipartisan and almost unanimously against. There was, actually, a moment when the country came together. But only a moment. Anti-government political forces began rolling through the streets, launching the infamous "Bangkok Shutdown" which eventually brought us the military regime and martial law.
The new, possibly improved, Constitution Drafting Committee (CDC) wants to revisit the idea of an amnesty. But if an amnesty is to help national reconciliation, it must first be acceptable.
At the moment, it is not. Deputy Prime Minister Wissanu Krea-ngam, the strongest pro-amnesty voice in the proceedings, must take steps to make the amnesty a genuine issue, not a divisive one. Here are some suggestions.
First, everyone must agree that "amnesty" is not a dirty word — only some forms constitute dirty tactics. Everyone can agree, surely, that a blanket amnesty is unacceptable. Some people suspected of certain crimes have to face justice and the court of public opinion.
So any discussion of an amnesty must include defining the exceptions. There can also be general agreement that there must be no amnesty without accountability. No person can even be considered eligible for legal forgiveness without addressing all offences.
The amazing and often emotional South African Truth and Reconciliation Commission sessions are the best guide possible. Perpetrators and victims of terrible crimes committed for political reasons confessed and forgave. Without such accountability, true amnesty is impossible.
Mr Wissanu advised last week that the nation approach the amnesty issue discreetly. Otherwise, debate will get heated and it will be impossible to include an amnesty in the new charter. This is the wrong approach. Only an intense debate will make some form of amnesty acceptable.
Amnesty and forgiveness can heal many wounds. Countries from South Africa to the Czech Republic's "velvet revolution" have shown the way to non-violent power transitions.
Mr Wissanu, the CDC and the public at large may eventually agree that an amnesty can halt division and help unity. But it will take a lot of work to convince this divided country.