For the high-order numerical approximation of hyperbolic systems of co
nservation laws, we propose to use as a building principle an entropy
diminishing criterion instead of the familiar total variation diminish
ing criterion introduced by Harten for scalar equations. Based on this
new criterion, we derive entropy diminishing projections that ensure,
both, the second order of accuracy and all of the classical discrete
entropy inequalities. The resulting scheme is a nonlinear version of t
he classical Van Leer's MUSCL scheme. Strong convergence of this secon
d order, entropy satisfying scheme is proved for systems of two equati
ons. Numerical tests demonstrate the interest of our theory.