A further step towards the emancipation of the senate from the power of the magistrates took place, when the adjustment of the senatorial lists was transferred from the supreme magistrates to subordinate functionaries - from the consuls to the censors[21]. Certainly, whether immediately at that time or soon afterwards, the right of the magistrate entrusted with the preparation of the list to omit from it individual senators on account of a stain attaching to them and thereby to exclude them from the senate was, if not introduced, at least more precisely defined[22], and in this way the foundations were laid of that peculiar jurisdiction over morals on which the high repute of the censors was chiefly based[23]. But censures of that sort - especially since the two censors had to be at one on the matter - might doubtless serve to remove particular persons who did not contribute to the credit of the assembly or were hostile to the spirit prevailing there, but could not bring the body itself into dependence on the magistracy.
But the right of the magistrates to constitute the senate according to their judgment was decidedly restricted by the Ovinian law, which was passed about the middle of this period, probably soon after the Licinian laws. That law at once conferred a seat and vote in the senate provisionally on every one who had been curule aedile, praetor, or consul, and bound the next censors either formally to inscribe these expectants in the senatorial roll, or at any rate to exclude them from the roll only for such reasons as sufficed for the rejection of an actual senator. The number of those, however, who had been magistrates was far from sufficing to keep the senate up to the normal number of three hundred; and below that point it could not be allowed to fall, especially as the list of senators was at the same time that of jurymen. Considerable room was thus always left for the exercise of the censorial right of election; but those senators who were chosen not in consequence of having held office, but by selection on the part of the censor - frequently burgesses who had filled a non-curule public office, or distinguished themselves by personal valour, who had killed an enemy in battle or saved the life of a burgess - took part in voting, but not in debate[24]. The main body of the senate, and that portion of it into whose hands government and administration were concentrated, was thus according to the Ovinian law substantially based no longer on the arbitrary will of a magistrate, but indirectly on election by the people. The Roman state in this way made some approach to, although it did not reach, the great institution of modern times, representative popular government, while the aggregate of the non-debating senators furnished - what it is so necessary and yet so difficult to get in governing corporations - a compact mass of members capable of forming and entitled to pronounce an opinion, but voting in silence.
The powers of the senate underwent scarcely any change in form. The senate carefully avoided giving a handle to opposition or to ambition by unpopular changes, or manifest violations, of the constitution; it permitted, though it did nor promote, the enlargement in a democratic direction of the power of the burgesses. But while the burgesses acquired the semblance, the senate acquired the substance of power - a decisive influence over legislation and the official elections, and the whole control of the state.
Every new project of law was subjected to a preliminary deliberation in the senate, and scarcely ever did a magistrate venture to lay a proposal before the community without or in opposition to the senate's opinion. If he did so, the senate had - in the intercessory powers of the magistrates and the annulling powers of the priests - an ample set of means at hand to nip in the bud, or subsequently to get rid of, obnoxious proposals; and in case of extremity it had in its hands as the supreme administrative authority not only the executing, but the power of refusing to execute, the decrees of the community. The senate further with tacit consent of the community claimed the right in urgent cases of absolving from the laws, under the reservation that the community should ratify the proceeding - a reservation which from the first was of little moment, and became by degrees so entirely a form that in later times they did not even take the trouble to propose the ratifying decree.