Taxation as slavery is the idea that taxation results in an unfree society in which individuals are forced to work to enrich the government and the recipients of largesse, rather than for their own benefit.
History
Historically, the earliest and most widespread form of taxation was the corvee, which can be traced back to the beginning of civilization. The corvee was state-imposed forced labor on peasants too poor to pay other forms of taxation (labor in ancient Egyptian is a synonym for taxes).
While slavery was a part of life in ancient Egypt, the Mediterranean, Rome, and Greece etc, many slaves received wages. For example, in some of the first records of taxation and slavery from over 5000 years, we see evidence that Egyptian Pharaohs only collected 20% tax on grain harvests, and yet the subjects were considered slaves at this high level of taxation, as is recorded in the book of Genesis 41:34-36
"Let Pharaoh appoint commissioners over the land to take a fifth of the harvest of Egypt during the seven years of abundance. They should collect all the food of these good years that...