Liberal Economics in the 18th Century had two wonderful laws to justify putting it to the poor and to workers.
Thomas Malthus wrote that as long as workers were well fed they would reproduce until they ran out of the ability to feed themselves, and population would collapse; therefore if workers were hungry that was not a bad thing,
David Ricardo was more specific; his “Iron Law of Wages” said that as long as there was a surplus of labor ('unemployed”), workers would compete for work until wages dropped to a level at which workers could not survive.
So if workers were poverty-stricken and making a subsistance wage, everything was fine.
Believers in this still say things like “People won't work if welfare is available.”