INTRODUCTION

Both the CISG (Art. 14(1)) and the PECL (Art. 2:101) recognize the traditional offer-acceptance model of contracting. The PECL also has a provision (Art. 2:211) on contracts not concluded through the traditional offer and acceptance mode.

Offer-acceptance, the only model explicitly addressed in the CISG, is the principal model in most legal systems of the world. However, it seems to be universally agreed that rules on the traditional model of offer-acceptance can be applied by way of analogy to other models, insofar as this is reasonable and with appropriate adaptations. The Comments on Art. 2:211 PECL may, in this respect, be relevant to the proper interpretation of the CISG.

ANIMUS CONTRAHENDI

The offeror expresses with his proposal the intention to give an option to the offeree: with the acceptance, the offeree can conclude the contract according to the terms of the offer. This intention has its Latin name: animus contrahendi. Both the CISG and the PECL demand animus contrahendi in an offer: the offer should show the offeror's “intention to be bound” in the case of acceptance (CISG Art. 14(1)), and an offer must be “intended to result in a contract if the other party accepts it” (PECL Art. 2:201(1)(a)).

THE “SUFFICIENT DEFINITION” OF AN OFFER

An offer is not only the manifestation of the offeror's intention to conclude the contract: as a project of a possible future contractual relationship, the offer must contain all of the elements necessary for the successful conclusion of a valid contract.