Guaranteed income is about money. Any discussions of guaranteed income must include the topic of money.
Money is a legal construct. That is why it is "legal" tender. Governments make money and give power to private banks to create money through lending. Of course this leads to the impossible problem of interest.
What you will find if you start researching money, is that there is no scientific basis for the money system. There are no rules that banks have to have a certain amount of reserves. The money supply is not based on the GDP, nor is it based on production (since all kinds of harmful things are counted as "Productive").
Some monetary reformists want to rationalize the money system by having money supply linked to productive capacity, however, who will decide on the definition of "productive" which counts as unproductive all the unpaid care work done on the planet, and counts as productive any activity that makes the economy grow -- regardless of whether that activity is harmful or wasteful of resources, the environment or people's lives.
Right now almost everyone in the world uses money to get the things they need to live. Maybe in the future, there will be a moneyless economy. But today we need money to live. A guaranteed livable income for every person in every country in the world means that we could transition to an economy not based on forced production and forced consumption -- things that waste natural resources, pollute, harm health and harm human relations and our relations with other living things.
Until we can come up with something better, a guaranteed income would give us a foundation to create change where everyone could participate -- not just those who have the luxury of not having to scamble everyday to survive.
Monetary Reform and Basic Income by Richard Cook: "In my opinion, it would be much more effective for the Federal Reserve simply to give away money" http://www.atlanticfreepress.com/content/view/1232/81/
Fail-Safe Humanity - a non-tax source for guaranteed income