In his discussion of kamus vs. eichus, R' Yosef Engel factors in another dimension: time. If X is qualitatively more significant thatn Y, but Y continues for a longer duration than X, does the factor of time cause Y to now outweigh X? An example of a sugya which seems to weigh these factors: the gemara (Kesubos 34b) presents two cases where a ganav who kills an animal is patur - 1) where the theft took place on Shabbos; 2) where the theft took place in a machteres. The common denominator in both cases is that the thief is subject to the death penalty and therefore exempt from double-jeapordy financial liability. Why, asks the gemara, do we need two cases to illustrate the same principle? Because, answers the gemara, had I just had the example of Shabbos, I might have thought the exemption from payment is due to the unique stringency of Shabbos. Shabbos is an "issur olam", meaning at any point in time that witnesses testify that someone has desecrated Shabbos, he would be killed; someone tunneling in a machteres can be killed only if he if caught in the act. Similarly, had I just had the example of machteress, I might have thought the exemption from payment is due to the unique stringency of that case. An intruder intent on buglary may be killed with no warning (hasra'ah), while there is no punihsment for desecrating Shabbos if the violator is not warned. The principle of exemption from payment is illustrated using both cases to show the exemption is not due to some stringency unique to one case or the other.
The punishment in a case of machteres has a qualitative edge over the punishment for desecrating Shabbos because it comes without any warning to the thief. Yet, Shabbos perhaps is more stringent because it is an "issur olam", without time limitation. Time tilts the scale toward the qualitatively lesser issur.
If you read yesterday's post or are learning daf yomi you will have come across the case (Nazir 47a) of a nazir and kohein who discover a meis mitzvah - which one of the two should become tamei to do the burial? R' Eliezer holds the kohein should become tamei and not the nazir. Since a nazir who becomes tamei must being a korban while a kohein suffers no such penalty, it proves the kedusha of a kohein is less significant than that of nazir. The Chachamim disagree and hold that the nazir should become tamei. Since the kohein is permanently in a state of kedusha (see Tosfos and Rashas"h) while the kedusha of the nazir is temporary, it proves the kedusha of the kohein superior.
The focal point of the debate seems to center around R' Yosef Engel's chakrira. Is the qualitatively superior kedusha of the nazir outweighed by the lesser kedusha of the kohein by virtue of the fact that kedushas kehunah has time on its side? SeeR' Yosef Engel's essay in Lekach Tov where he suggests other approaches to explain the Mishna's debate, but this approach certainly seems compelling.