Aulus Gellius’ Attic Nights, XIII.XV, 1-7

In the edict of the consuls by which they appoint the day for the centuriate assembly it is written in accordance with an old established form:

“Let no minor magistrate presume to watch the skies”.
Accordingly, the question is often asked who the minor magistrates are. On this subject there is no need for words of mine, since by good fortune the first book of the augur Messalla ‘On Auspices’ is at hand, when I am writing this. Therefore I quote from that book Messalla’s own words:
“The auspices of the patricians are divided into two classes. The greatest are those of the consuls, praetors and censors. Yet the auspices of all those are not the same or of equal rank, for the reason that the censors are not colleagues of the consuls or praetors, while the praetors are colleagues of the consuls. Therefore neither do the consuls or the praetors interrupt or hinder the auspices of the censors, nor the censors those of the praetors and consuls; but the censors may vitiate and hinder each other’s auspices and again the praetors and consuls those of one another.
The praetor, although he is a colleague of the consul, cannot lawfully elect either a praetor or a consul, as indeed we have learned from our forefathers, or from what has been observed in the past, and as is shown in the thirteenth book of the Commentaries of Caius Tuditanus; ‘for the praetor has inferior authority and the consul superior, and a higher authority cannot be elected by a lower, or a superior colleague by an inferior.’
At the present time, when a praetor elects the praetors, I have followed the authority of the men of old and have not taken part in the auspices at such elections. Also the censors are not chosen under the same auspices as the consuls and praetors. The lesser auspices belong to the other magistrates.
Therefore these are called ‘lesser’ (minores) and the others ‘greater’ (maiores) magistrates. When the lesser magistrates are elected, their office is conferred upon them by the assembly of the tribes, but full powers by a law of the assembly of the curiae; the higher magistrates are chosen by the assembly of the centuries.
The praetor is a colleague of the consul, because they are chosen under the same auspices. They are said to possess the greater auspices, because their auspices are esteemed more highly than those of the others.”

Aulus Gellius’ ‘Noctium Atticarum’, XIII.XV, 1-7