1. The possible effects of illegality

(a) Subdivision of statutes according to their sanctio

Illegality is the second of the general grounds of invalidity referred to above. Broadly speaking, it can be described as a situation where either the conclusion or the content of a contract infringes a statutory prohibition.

¹³⁹ Trans. Weir, in Zweigert/K6tz/Wt?ir. p. 161.

^u" But cf. Arp. Atifaneliche Utimoelichkeit, pp. 155 sqq. (who. however, also advocates a restriction of § 306 BGB1.

¹¹ Cf. Zweigert/Kotz. p. 228 and Couturier v. Hastie (18561 5 HLC 673. the leading case in this field of the law. which turned upon the construction of the contract. On this case, see F.S. Atiy ah," Couturier v. Hastie and the Sale of Non-Existent Goods". (19571 73 LQR 340 sqq. (hut see now Atiyah. Essays, p. 2501. For South African law cf. Christie. Contract, p. 82.

e.g. Trcitel. Contract, p. 214.

Cf. supra, p. 693 (note 1161.

^1,1 Carlo Gioffredi. "La 'sanctio' della leggc e la 'perfectio' della norma giuridica". (19461 2 Archivio penale 166 sqq.. 174 sqq.

(b) Leges minus quam perfectae

It is particularly the existence of the latter category that tends to surprise the modern observer. Was it at all sensible to enact leges imperfectae? What hope could a legislator realistically have that his directions would be followed if, essentially, they merely constituted an appeal to the good will of the people?^[3519] In order to answer these questions, we must first of all take account of the fact that the oldest lex perfecta of which we can be certain dates from 169 B.C.^[3520] In the early days of Roman law the validity of a transaction seems to have been judged only from the point of view of the required form. If the formalities were not complied with, the transaction was invariably and irremediably void; where, on the other hand, they had been observed, it was unquestionably valid. That statutory prohibitions could interfere with, and indeed completely invalidate, formal private acts was inconceivable to the lawyers and law-makers of the earlier Republic; it was an idea that required a refined capacity of abstraction and analysis.^[3521] Thus, before approximately the middle of the second century, the Roman legislator was forced, if he wished to strengthen the efficacy of a statute, to sanction its violation by the imposition of a penalty. And, indeed, statutory prohibitions in the form of leges minus quam perfectae were the rule during this period. The lex Furia testamentaria (fixing the maximum amount of a legacy that a person was allowed to receive at one thousand asses)^{[3522] [3523] is one example, 0 the various attempts to fight the taking of excessive interest by fixing certain "ceiling-rates"[3524] [3525] [3526] [3527] [3528] provide us with another.}

(c) Leges imperfectae

Leges imperfectae, even in the old days, were resorted to only in exceptional circumstances. Invalidity of the transaction was out of the question; but sometimes special policy considerations prompted the legislator not to impose a penalty either. The lex Cincia de donis et muneribus provides the best example of this strange kind of compromise. It prohibited donations exceeding a certain amount and was designed to prevent rich and influential members of the establishment from extracting excessive and not always voluntary "gifts" from (amongst others) their clientes.¹⁵³ On the other hand, however, one did not want to embarrass the leading circles of society by exposing them to court proceedings and the concomitant publicity.¹⁵⁴ Quieta non movere was the precept of the legislator, which was carried through even when it came to determining the legal consequences of an act infringing the provisions of the lex.¹⁵⁵ A donation exceeding the limit was not invalid, and hence there could be no (enrichment) claim against the recipient of the gift. Where, however, the donor had so far merely promised to make the prohibited donation, he could not be sued by the promisee either; for the praetor, in his decision whether or not to grant an action, had to be guided by the fact that the promise had been made in violation of a statutory prohibition (albeit an "imperfect" one). A praetor who would have allowed an action under these circumstances would himself have been guilty of a violation of the legal order.^[3529] Denegatio actionis was the appropriate course for him to take.^[3530] Under the more modern formulary procedure the exceptio legis Cinciae became the standard way of bringing the illegality to judicial cognizance.