  We present a novel treatment of finite temperature properties of the
one-dimensional Hubbard model. Our approach is based on a Trotter-Suzuki
mapping utilizing Shastry's classical model and a subsequent investigation of
the quantum transfer matrix. We derive non-linear integral equations for three
auxiliary functions which have a clear physical interpretation of elementary
excitations of spin type and charge excitations in lower and upper Hubbard
bands. This allows for a transparent analytical study of certain limiting cases
as well as for precise numerical investigations. We present data for the
specific heat, magnetic and charge susceptibilities for various particle
densities and coupling strengths U. The structure exposed by these curves is
discussed in terms of the elementary charge and spin excitations. Special
emphasis is placed on the study of the low-temperature behavior within our ab
initio approach confirming the scaling predictions by Tomonaga-Luttinger liquid
theory. In addition we make contact with the ``dressed energy'' formalism
established for the analysis of ground state properties.
