In economic science and policy, the term "capital"—used to mean capital, a capital, or some capital—seems at first glance to pose few problems. Upon closer examination, a consistent and unambiguous definition emerges that clarifies its role in the economic landscape, including the modalities of ownership of enterprises (see negotiable versus returnable shares).
Full employment and the avoidance of financial crises depend more than any other magnitude on capital as permanent financing of enterprises. This leads to a system of weights and measures that provides controlling and emancipatory instruments.