Although you could argue that the right to decide is at the forefront of one of the most important political processes that our nation has ever gone through, I realise that it is looked down on as a vague, imprecise concept, lying somewhere between political marketing and literary fiction, even by some of its defenders. Indeed, the right to decide has been a tool for political action and has contributed to defining the political game in certain terms, as opposed to others. In communication theory, we call this "framing". The dispute over this framing is part of the political struggle and it may ultimately account for the victory, to some extent.
Besides, especially those who oppose the process have ended up twisting its original meaning when they claim that the right to decide belongs to all Spaniards; or that Catalans already exercise this right every time they vote in ordinary elections. Spain's Constitutional Court also used it in this sense when it ruled on the sovereignty declaration, stating that "a constitutional interpretation of the right to decide is possible". All these considerations are an attempt, --self-serving or born out of ignorance-- to render the main legitimising reason for Catalonia's independence void of content, if it ever happens. Therefore, it is no moot point. It would be wise to understand what we are dealing with here.
Let's start by establishing what it is not. The right to decide is not the right to consult or be consulted. Indeed, it is necessary to know the people's opinion in order to make a decision and, in the current circumstances, this right must also be demanded. Even though it may be part of the "exercise of the right to decide", opining and deciding aren't the same thing. The right to decide is not the right to vote on November 9.
The right to decide is not the right to self-determination, either. There is a precise, well-established concept for that in international law, which recognises that decolonisation processes must incorporate the right of former colonies to decide on their political future through a referendum. This concept is rarely questioned: no international forum would doubt that Western Sahara needs a self-determination referendum, just like nobody would claim that right for Catalonia.
When the Plataforma pel Dret a Decidir (Platform for the Right to Decide, 2006) began to use this term extensively, there wasn't enough awareness of what it meant yet. For some it was merely a novel way of wording Catalonia's hypothetical claim to self-determination. For others, though, it meant something different: arguing that the Catalan people should always have the last say on Catalonia's political affairs. This right was demanded in that sense during the Statute negotiations in Madrid: "We are a nation and we have the right to decide". Even a year later, during the railway chaos, thousands of people summoned by the PDD and trade unions shouted: "We are a nation and we have the right to decide about our infrastructures."
Recognition of a stateless political subject and the ability to decide: how far?
In 2010 the International Court of Justice indirectly addressed this question in its ruling on Kosovo's declaration of independence, reiterating what the Supreme Court of Canada had ruled on the matter of Quebec, but taking it a step further. From the conclusions of this ruling, one could define the right to decide as a legitimising political principle by which, if a political subject wishes to become a new state and can do so because it is viable and respects the basic rights of all its citizens, it should be allowed to go ahead, even if there is no colonial relationship, on condition that it's a peaceful, democratic process and all attempts to reach an agreement with the state have failed.
This principle is not grounded in the ICJ, which merely reflects it, but in the fact that in the 21st century there should be a formula to resolve such conflicts efficiently and without resorting to violence. In the 21st century no state should be seen as a moral principle that must be preserved. In the 21st century, the necessary interdependences, globalisation and military stability allow us to exercise the ideal that national borders can be changed if that is the decision of the people, after considering the pros and cons. Fiction? Perhaps, for now. So was Locke's right to rebellion that American revolutionaries exercised. Eventually, if we become a new state, the main argument to explain ourselves --and the main source of fundamental legitimacy for Catalan independence-- will be the right to decide.