Hi, Reiver - the lyrics you posted right above are the Kevess translation that appeared in Sing Out! Magazine in 1950, and in The Collected Reprints from Sing Out!, and in Sing Out's Rise Up Singing songbook. Note that these publications end both the first and second verses with:

Es bleibet dabei:
Die Gedanken sind frei!

I'd guess this is a mistake, and that the lyrics Wolfgang posted are the correct ones. for the first verse, Wolfgang, posted: Why would the first two verses end the same, and all the others end differently? In the first verse, Wolfgang has:

Kein Mensch kann sie wissen,
Kein Jäger erschießen
Mit Pulver und Blei.
Die Gedanken sind frei!
No person can know them (thoughts), no hunter can shoot them with powder and lead.

Songs of Work and Protest (Edith Fowke and Joe Glazer, 1960) has the same Kevess translation of the first three verses, and the same German verses as the Sing Out! books. (I'm guessing the fourth verse, as posted by Joan from Wigan, was translated by Gerda Lerner). Here are the notes from Fowke/Glazer:

This old German folk song is said to date back more than four hundred years. It apparently sprang from the Peasants' War of 1524-26, when the oppressed peasants revolted against increased exploitation by the nobles. Unfortunately, the peasants were routed by the princes of the Swabian League, and their defeat prolonged serfdom in Germany for nearly three centuries, stunting democratic development. However, this fine song continued to be sung whenever Germans made a new attempt to gain freedom. Schiller put it in one of his plays, and the German student movement took it up. It was widely sung in the schools of pre-Hitler Germany and German immigrants brought it with them when they came to this continent.

Reiver, your Work and Sing songbook is still in print, available from World Around Songs. The translator of "Die Gedanken Sind Frei" is identified only as "KF." Yes, it's a translation of the same (questionable) German text Kevess used - you have to stretch a bit to see it, but the two English versions are translations of the very same German text, in the very same order of verses. Both translations are quite good.

Kevess, by the way, did a very nice translation of the Yiddish song, "Hob Ikh Mir a Mantl" (I Had a Little Overcoat) and Finjan, and the definitive translation of Dona Dona.