Watt introduced a design enhancement, the separate condenser, which avoided this waste of energy and radically improved the power, efficiency, and cost-effectiveness of steam engines. Eventually he adapted his engine to produce rotary motion, greatly broadening its use beyond pumping water.
The correct answer is slavery
Slavery, is the social practice in which a human being acquires property rights over another called a slave, to whom this condition is imposed by force.
In some societies, since the most distant times, slaves were legitimately defined as a product. Prices changed according to physical conditions, professional skills, sex, age, origin and destination.
When we speak of slavery, it is difficult not to think of the Europeans who overcrowded the holds of their ships of men brought from Africa regardless of their wills and who were put up for sale in an inhuman and cruel manner throughout America.
The Enlightenment was an 18th century philosophical movement. One of their favorite words was 'reason.'