The social prestige of professions with higher education, exercised by social assistants, biologists, dentists, nurses, engineers, pharmacists, physicists, physiotherapists, phonoaudiologists, physicians, chemists and sociologists, was scaled by using both the indirect ordering method and the direct psychophysical category and magnitude estimation methods. The results showed: (1) high correlation (rho = 0.97) between the prestige levels attributed to the professions, obtained by the three psychophysical methods, (2) the non-metric continuum of professional prestige exhibited prothetic characteristics (rho = 0.96); (3) the relationship between the magnitude estimates and category estimates is a semi-logarithmic function, and (4) the variability of magnitudes estimates, indicated by the standard error of geometric mean, was a linear function of the geometric mean of the magnitude estimates, thus confirming that Ekman's law is also valid for non-metric continua. In short, the data showed that the scale of social prestige possesses quantitative or prothetic characteristics, and not qualitative or metathetic ones.