After reading an excellent article on immigration reform and free trade by Benjamin Powell, I was depressed by the numerous knee-jerk mindless comments of those that have been indoctrinated into the belief that all good in this world can only come at the end of a stick-wielding state… that the state is the last thing that stands between “the people” and evil rich people who are poised to take over the world and put us all into chattel slavery. Anyway, I picked one of the most obtuse comments and made a comment, you can see the whole thing here, but here are the highlights:

Commenter says: “The basic case for free trade builds upon the fact that different people, in different places, have different abilities to produce goods and services.” That is not a basic case – it says nothing about who will benefit and who will lose. 
So called Free trade has ruined people in Africa, South America, Latin America, and now in the USA.”

So then I say “You don’t really understand what trade is do you? Nobody loses in trade. The only reason people trade is that they value what the other person has more than they value the thing they are giving up to get it. Both sides “profit” from trade. “Free trade” has not ruined the peoples you cite – Marxist/totalitarian governments who keep their people poor by confiscating all wealth created have ruined them. Because the standard of living in those countries is not the same as it is in the US is not the fault of free trade… we’ve just been doing it longer than they have. That’s like saying school is harmful because you compare a 12th grader to a 1st grader and blame school on the fact that the 1st grader can’t do calculus like the 12th grader can. Ceteris paribus. You aren’t making an apples to apples comparison.”

Someone else says “You don’t understand trade. You probably took Econ 200 and think you know something. You probably learn “comparative advantage” but never learned “absolute advantage”. Also would you consider trade with slave masters a “win win”? How about trade with cannibals? What about trade with a brutal dictatorship?”

So then I say: “There is no “absolute advantage” in trade – “absolute” is a term reserved for the physical sciences where one can make objective “absolute” measurements, i.e. mass = 20 g, temp = 25 °C, 12 neutrons in a carbon atom, etc. Economics is the study of value, and value is subjective… 

To your points: Trade with slave masters: (I presume you mean between the slave master and the slave) that is not trade by definition, trade can not be coerced, if the process of exchange is coerced then it is theft, not trade.
Trade with cannibals: is this a joke? who is trading with cannibals?
Trade with a dictatorship: this is similar to your slave master example although here I presume you mean trade of a “normal” person with the slave master himself (in this case the dictator who enslaves his populace)… so no, of course that is not “win-win” for everyone but it has nothing to do with fact that trade is occurring, it has to do with the fact that one party gains their advantage by stealing from others (the citizens so enslaved). 

You’re straw manning the argument here, no different then implying trade can be bad if a thief engages in trade. Well that is “bad” not because it is trade, but because one party is a thief. If a thief eats hamburgers does that make eating hamburgers bad? No, well then it doesn’t make trade bad either just because a criminal engages in it.”