What are the consequences of modernity for the institution of contracting? As the unity of the traditional contract is dissolved into a multiplicity of separate contracting worlds (economic transaction, legal promise, productive agreement), the binding force of contracting needs to be reformulated from an interpersonal to an interdiscursive relation. The central thesis of this Article is that the unity of contracting is hidden in the blind spot of the distinction between contracting worlds. Contracting needs two diametrically contradictory but complementary theories which cannot be integrated into a synthesis. As demonstrated with the example of the expertise contract, the subtle interplay of different contracting worlds depends basically on a fragile symmetry of chances of translation. The normative correlate of contract understood as translation between different worlds of meaning would be an extension of constitutional rights into the context of private governance regimes.