how are you a premium member?Not very much syntax technique aside from the prose and high modality. Using the full quote 'they are animals that are free' uses animal metaphor/ zoomorphism : )
general rule for 1984: if anything is high in modality and uses lucid prose syntax, assume it mimics political texts (Russian propaganda, socialist manifestos etc)
This particular paradoxical chiasmus is really sad imo, it's a very defeated moment where the power of utilitarian and totalitarian government over individual action is truly captured. T___________TI think the quote that come after this is
"Until they become conscious they will never rebel, and until after they have rebelled they cannot become conscious."
from chapter 7 part 1, I am bad at English but there may be techniques when it is juxtaposes with this one, hope this may help you