If the government doesn't intervene, there's no control, so sellers can do whatever they please. Hence price fixing, dumping, monopolies, etc., are all possible in a free market. There's no contradiction.
> [If] price is not set by supply and demand, [...] you do not have a free market
You can't even define what "set by supply and demand" means. Supply and demand are variables in some equation that does not and cannot capture reality.
- price of goods is set by supply and demand
- the government doesn't intervene (for example through subsidies)
Price fixing is defined by:
- all the sellers (or buyers) agreeing on and therefore setting the price
- price is not set by supply and demand, therefore you do not have a free market
If the government doesn't intervene, there's no control, so sellers can do whatever they please. Hence price fixing, dumping, monopolies, etc., are all possible in a free market. There's no contradiction.
> [If] price is not set by supply and demand, [...] you do not have a free market
You can't even define what "set by supply and demand" means. Supply and demand are variables in some equation that does not and cannot capture reality.