Bearing assemblies and apparatuses are disclosed. Such bearing assemblies may be employed in bearing apparatuses for use in downhole motors of a subterranean drilling system or other mechanical systems. In an embodiment of the present invention, a bearing apparatus includes a first bearing assembly including a first substantially continuous polycrystalline diamond bearing surface defining an annular surface, and a second bearing assembly including a second substantially continuous polycrystalline diamond bearing surface defining an annular surface. The second substantially continuous polycrystalline diamond bearing surface generally opposes the first substantially continuous polycrystalline diamond bearing surface.