In the experimental hypnotism, the yardstick for a good subject was its constancy in displaying certain symptoms that could be translated into a regular curve.
Exploiting the assumed constancy of the rate of return on savings, marginal utility is treated as a fixed effect.
The constancy assumption implies that it is not affected by impulses hitting the system.
Furthermore, caring for and maintaining an object's identity not only renders it identifiable among other objects; it also introduces a relative constancy over time.
Overall constancy in volume during deformation is suggested from the balance between fracture-related grain-scale dilatancy and solution-related volume loss.
Further, because chromatic contrast requires only wavelength sensitivity, but constancy requires something more, it is likely that contrast evolved first.
The phenomenon of shape constancy may also be relevant to the question.
Moreover, both the principle of relativity and the constancy of the speed of light are connected with fundamental symmetry considerations.
