The Future of Work and Income

What is work? Should work always be paid? If so, on what basis (e.g. according to sheer number of hours worked, effort made, scale of economic or other contribution, level of qualification)? Should governments guarantee their citizens income, or the opportunity to work, or both? Why is it possible for some to earn income without working at all, and should this be the case? How should we, as a society, decide what work is done, who does it, and how its products are distributed? Can our current systems and institutions for deciding this survive the coming demographic and technological transitions? Would the ideal future be a world without work, or where work is always fulfilling, or something else?