We adapt an earlier semiclassical theory of laser cooling of an arbitrary multistate atom to the limit of low light density. The formal theory is implemented analytically on a computer using Mathematica. Expressions of light-pressure force and diffusion are provided for j_1 = 1/2 -> j_2 = 3/2 and j_1 = 1 -> j_2 = 2 atoms in a one-dimensional optical confinement area in which the pair of counterpropagating waves has orthogonal polarizations. In our models the cooling temperature decreases as the level degeneracy increases.