An exhaustive analysis of finite plastic straining of f.c.c. crystals in the sixfold, tensile symmetry position is presented. Classical Taylor hardening and the 'simple theory' of finite-distortional latent hardening serve, in turn, as a basis for the theoretical studies. For prescribed axial loading, wherein each theory permits a variety of strain-rates and axis rotations, a quasi-energetic postulate is found that constrains (or partially constrains) the solution to that which appears physically most likely: axis stability accompanied by axisymmetric deformation. The two theories are contrasted with one another, with positive-definite hardening rules (which are briefly considered), and with diverse empirical evidence that defines the essential features of finite deformation and latent hardening of f.c.c. crystals in a variety of single- and multiple-slip orientations. It appears that only the simple theory, augmented by a minimum-work postulate, is consistent with this diverse evidence.