ORIGINAL: Jorge_Stanbury
The original phrase is probably very old, and I bet there is some form of idiomatic variation in every language. It also comes to the fact that in the english language, one word; "free" means two concepts.
Spanish for example, we have 2 specific words: "gratis" = for "without a cost" and "libre" = for "having freedom"
Liberal economists have been using it, quite successfully, to explain that these 2 concepts are different; and to warn that for the left economist, free means "let someone else pay for it"
Bringing Milton F. into this thread is what I would characterize as a political statement, which those of a conservative bent get away with, as here, but I get called down for challenging. So I won't. If you are not American you may be unaware of Mr.F's standing in the politico-economic wars of recent decades. So I'll let that lie there.
In English "free" has many, many definitions, as do lots of words. (As an aside, I have been told by ESL teachers that "point" has the most dictionary definitions of any common English word. It is often used by them as an example for students learning English of "this is as bad as it gets.")
In English we use "gratis." We use "liberty."
Also "free." "Costless." "Independant." "Autonomous." "Emancipated." "Unsupervised." "Democratic." "Unburdened." And dozens more synonyms with slightly different flavors and usage occasions.