Results are presented on the X-ray emission from 13 objects, observed by Ginga as part of a spectral survey of bright quasars in the energy range 2-20 keV. The distribution of the power-law energy index for this sample has a mean of 0.81 and shows significant intrinsic dispersion, σ = 0.31, values which are broadly compatible with those from samples of lower luminosity active galactic nuclei. The mean spectral slope is clearly too sleep to fit the spectrum of the cosmic diffuse X-ray background (CXB) at energies less than 20 keV, confirming the spectral paradox in the discrete-source explanation of the CXB