Pufendorf: On the Duty of Man and Citizen according to Natural Law

1. Agreements [pacta] form a kind of bridge between the absolute and the hypothetical duties. For all duties, apart from those already discussed, seem to presuppose agreements, whether express or tacit. This then is the place to discuss the nature of agreements and what should be observed by those entering into them.

2. It is quite clear that men had to enter into agreements with each other. For although duties of humanity pervade our lives, there is no way that one could derive from that source alone every benefit that men might legitimately expect to receive from each other to their mutual advantage. In the first place, not everyone has such goodness of heart that from sheer humanity he would be willing to give others whatever would do them good without looking for an equal return. Again, benefits we might derive from others are often such that we cannot without a feeling of shame require them to be simply given to us. Often too it is not appropriate to our person or position to be beholden to another for such a kindness, so that just as the other is unable to give, so we are unwilling to accept, unless he takes something equal from us in return. Finally, it happens from time to time that others are simply not aware how they may serve our ends.

It was therefore necessary for men to make agreements with each other so that the duties which they perform for each other (and this is the advantage of sociality) might be performed more frequently and in accordance with what one might call fixed rules. This is particularly true of the mutual provision of the sort of things which a man could not surely count on getting from others on the basis of the law of humanity alone. Hence a prior determination had to be made as to what one man should do for another and what he should expect in return and might claim in his own right. This is done by means of promises and agreements.