Emancipation
Soul vs. bone
The 'mortal bone' is the physical body—temporary, destructible. The soul 'knits' inside it like a separate structure, permanent and untouchable.
Scymitar spelling
Archaic spelling of 'scimitar' (curved sword). Dickinson pairs medieval torture (rack, saw) with Eastern warfare—cataloging every way bodies get destroyed.
Eagle simile pivot
The comparison flips mid-sentence. You can't strip the eagle from its nest any easier than you can strip yourself from your soul—but the 'thou' here suddenly addresses the reader.
Final paradox
Both captivity and liberty exist only in consciousness—in how you think about yourself. The whole poem collapses into this: freedom is mental, not physical.