Isobaric Spin without Charge Space

The familiar consequences of charge-independence of a nuclear Hamiltonian are derived without introducing the concept of charge space and the extended Pauli principle. Ordinary wave-functions, separately antisymmetric in their protons and neutrons, are used throughout. This has the pedagogical advantage of emphasizing that the physical regularities associated with isobaric spin are consequences of charge-independence alone, and do not depend upon the charge-space formalism.