The Roman's attachment to forms was not confined to the private law, and the Englishman may well sympathize with it when he considers the extent to which, particularly in public affairs, he himself adheres to forms even when they have lost their original significance. Moreover there are sound practical reasons for requiring formality in some parts of the private law. Forms give certainty and clarity to an act—they serve not only to make precise the character of what is done and to mark the moment of its completion, but also to make the parties stop on the brink of the act and thereby to ensure that they know that the decisive moment has come.
On the other hand forms have the disadvantage of inflexibility and often of inconvenience. In modern law, on the whole, contracts are informal but acts concerning the conveyance of land or the passing of property on death are formal, though the form is usually simple. Roman law differs from most other systems both in what has been called its 'economy of forms' and in the simplicity of the forms themselves. It makes a very small number of forms serve a wide variety of purposes, and the forms contain little that is not necessary for defining and making evident the inner purpose of the act.
The forms of Germanic law, by contrast, were much more diverse and had much that was merely picturesque or dramatic. There were four main forms. One of these, the stipulatio, an oral question and answer, was used only in the law of contract. The others appear in slightly different guises and in different combinations in different parts of the law, and are prominent in the law of persons. They can therefore most conveniently be treated together at the beginning.
Act before the comitia curiata was the least important of the three forms, was ostensibly a legislative act—a 'private bill'—and was used for one kind of adoption and for the earliest form of will. The comitia curiata which 'passed the bill' was the oldest of the Roman assemblies, but in historical times it had no substantial existence as a legislative body, the thirty curiae of which it was composed being represented by the thirty lictors who were in attendance on the presiding magistrate. The substance of the proceedings was therefore the magistrate's approval of a private act.
Very early, however, the Romans found it convenient to accord limited rights under the ius civile to their immediate neighbors, the Latins, and a similar status was later allowed to the growing number of colonies which the Romans established as their rule spread. This status, between that of citizen and peregrine, continued to be called 'Latinity' though by the end of the Republic it had long ceased to have any geographical or ethnical significance. Nor were the privileges it conferred always the same. One must distinguish here three different rights.
Commercium (or ius commercii) was the right to be a party to a mancipatio and perhaps to use some other specifically Roman methods of acquiring property and making contracts; conubium (ius conubii) was the right to contract with a Roman citizen a marriage recognized by the civil law; testamenti factio was the right to make, and take under, a Roman will. All Latins had commercium, some at least had testamenti factio, and few had conubium. Latinity was not, however, the most that the non-Roman could aspire to.
Although grants of citizenship were rare until the last years of the Republic, the Romans then relented. By the end of the Republic the citizenship had been extended to all Italy, and grants were frequently made by the Emperors either to whole communities or to individuals. Moreover the slave population provided a never-failing source of new citizens. For, with rather surprising generosity, the Romans conceded to their manumitted slaves the privilege which as late as 91 B. C. at the cost of a bitter war they refused to their Italian allies.
A new class was created by a lex Junia, which accorded Latinity, but without conubium or testamenti factio, to imperfectly manumitted slaves (Junian Latins). In the early years of the Empire the promise of citizenship was increasingly used as an instrument of policy to attract these and other Latins into activities in the public interest—the building of houses, the shipping of grain to Rome, service in the fire brigade (a matter of great importance in so crowded and inflammable a city as ancient Rome), the bearing of children, and so forth.
In the result, any enterprising Latin must have been able to raise himself to the citizenship. The importance of the distinction between citizen and non-citizen largely disappeared after the grant of the citizenship in A. D. 212 to the bulk of the population of the Roman world, though Junian Latins seem to have been excluded from this grant.