The theory of polar fluids is discussed from a physical standpoint. Field equations and constitutive equations are established from a different point of view. Using the entropy inequality, restrictions on material coefficients are obtained. Various boundary conditions are discussed and a new boundary condition is suggested. The classical slow motion concept is extended to the case of polar fluid motion. The expression of the increased rate of dissipation in an incompressible suspension is given and the viscosity of a dilute suspension is calculated. A convenient expression for the force exerted by the fluid on a body is established and the expression of the force by fluid on a rigid sphere in uniform translation is obtained.