The Circulation of capital (n.) is a spiral, an ever-widening curve, not a simple circle.
The Circulation of capital (n.) is a constant process of interruption: each stage conditions the next and at the same time excludes it.
The Circulation of capital (n.) is a perpetual motion machine: where the circulation of money dies out in money as a static thing, capital keeps setting itself alight again.
The Circulation of capital (n.) spans production and exchange, so that the independence of circulation and the otherworldliness of production both turn out to be mere semblance.
The Circulation of capital (n.) is its becoming, its growth, its life process; if anything deserves comparison with the circulation of the blood, it is this, not the empty circulation of money.