 S Software Agents and Contracts Francisco Andrade Universidade do Minho, Portugal Paulo Novais Universidade do Minho, Portugal José Neves Universidade do Minho, Portugal Copyright © 2008, IGI Global, distributing in print or electronic forms without written permission of IGI Global is prohibited. IntroductIon In the current economical context, characterized by the existence of a global society, the access to information is crucial for any economical and social development; yet, important technological challenges still remain. The representation, maintenance, and querying of in- formation is a central part of this problem. How can we obtain the adequate information at the adequate time? How can we supply the correct items for the correct people at the correct time? How and where can we get the relevant information for a good decision-making? The organizations focus their competences in strategical areas and have recourse to external supplies, cooperating with sporadic partners, with the objective of reducing costs, risks, and technological faults or maximizing benefts and business opportunities. One of the most radical and spectacular changes is the information de- materialization, the procedure automation, the recourse to decision support systems or intelligent systems, and to new forms of celebrating contracts (e.g., is it possible to practice commercial acts and celebrate deals using autonomous and pro-active computational agents?). The virtual organizations face new challenges and there must be a search for new answers to old questions. The negotiation processes through electronic means and the e-commerce platforms may set new forms of contracts, with engagements and negotiations among virtual entities. Software agents are computational entities with a rich knowledge component, having sophisticated properties such as planning ability, reactivity, learn- ing, cooperation, communication, and the possibility of argumentation. The use of the agent fgure is par- ticularly adequate to such problems. The objective is to build logical and computational models, as well as implementing them, having in consideration the law norms (i.e., legislation, doctrine, and jurisprudence). Agent societies may mirror a great variety of human societies, such as commercial societies with emphasis to behavioral patterns, or even more complex ones, with pre-defned roles of engagement, obligations, contractual, and specifc communication rules. To begin with, it must be said that under western legal systems, computers totally lack legal personal- ity (i.e., the possibility of being subjects of rights and obligations, of expressing a valid and binding will, of being liable for their own actions). However, intelligent artefacts are not only capable of acting according to its in-built knowledge and rules, but prove to be capable to learn from experience, modify its own states of knowledge, in particular according to cognitive, reac- tive and pro-active processes quite similar to those of the human beings. Of course, the consideration of such behaviours and their role--the role of the computer is rapidly evolving from that of passive cipher to that of active participant in the trading process--operates a radical shift in the way we understand basic legal questions such as will and declaration, or the means of manifesting a will in order to get legal effects produced (Portuguese Civil Code, art. 217º), which leads us to an imperious need of analyzing the question of expression of consent in itself. And two main possibilities have been analyzed: the possibility of considering the electronic devices as mere machines or tools, used by its owner and the daring possibility of considering the electronic device as a legal person. LegaL consIderatIon of software agents One possibility would be to consider the whole declara- tive process as indeed performed by a human. It would be like establishing a legal presumption that—Allen Andrade F., Novais P., Neves J., Software Agents and Contracting, Encyclopedia of Networked and Virtual Organizations, Goran Putnik and Manual Cunha (Eds), Idea Group Reference, ISBN 978-1-59904-885-7, 2008.