  We give an axiomatic characterization of maps from algebraic K-theory. The
results apply to a class of maps from algebraic K-theory to any suitable
cohomology theory or to algebraic K-theory, which includes all group morphisms.
In particular, we obtain comparison theorems for the Chern character and Chern
classes and for the Lambda and Adams operations on higher algebraic K-theory.
We show that the Adams operations defined by Grayson agree with the ones
defined by Gillet and Soule.
