Itsurō Sakisaka

 (向坂 逸郎, February 6, 1897 - January 22, 1985) was a Japanese Marxian economist.

Exploitation of Labor (1967)
One section of Sakisaka's 1967 book of Shihon-ron Nyumon (Introduction to Das Kapital), translated by Michael Schauerte and cited in Marxists.org
 * The idle lives of a minority ruling class can only be maintained by products, needless to say. So the only method to bring about this state of affairs is to appropriate, gratis, the fruits of labor of those who work by the sweat of their brow.
 * In the case of the exploitation of slave labor, by contrast, things are exceedingly clear. Slaves, who exist as a sort of animal owned by another human being, have no freedom. Like a dog, a slave is unable to exercise any degree of physical or mental freedom.
 * A newspaper article - I can't recall the exact year - listed the capitalist Kōsuke Matsushita as the person in Japan with the largest income. I don't know anything about Mr. Matsushita personally, and just happened to see this article, but here I would like to use his case to illustrate exploitation. This example, incidentally, will assume that products and labor-power are sold at their value.
 * Since the labor-power could be the labor of four, eight, or even twelve hours, the amount of labor expeneded can be augmented. The value of the labor-power is decided by the consumption goods necessary to maintain the life of the worker, making it possible for that person to exist as a human being who expends the same labor today as yesterday.
 * Once the means of production have become capital, a certain quantity of value is augmented through the exploitation of labor. And this valorizing value is capital.
 * Marx refers to the value invested on the means of production as constant captial.