Fixed point theorems for
uniformly lipschitzian mappings often restrict the characteristic of convexity, 𝜀0(X),
of the underlying Banach space to be less than one. This condition is discussed; in
particular, it is shown that, for Banach spaces, 𝜀0(X) < 1 is equivalent to a condition
imposed by E. A. Lifschitz in arbitrary metric spaces. The stability of this condition
with respect to Banach-Mazur distance and Lebesgue-Bochner function spaces is also
considered.