For the question is not of promises mutual, where there is no security of performance on either side; as when there is no civil power erected over the parties promising; for such promises are no covenants: but either where one of the parties has performed already; or where there is a power to make him perform; there is the question whether it be against reason, that is, against the benefit of the other to perform, or not. And I say it is not against reason. For the manifestation whereof, we are to consider; first, that when a man doth a thing, which notwithstanding anything can be foreseen and reckoned on, tendeth to his own destruction, howsoever some accident which he could not expect, arriving may turn it to his benefit; yet such events do not make it reasonably or wisely done. Secondly, that in a condition of war, wherein every man to every man, for want of a common power to keep them all in awe, is an enemy, there is no man who can hope by his own strength, or wit, to defend himself from destruction, without the help of confederates; where everyone expects the same defence by the confederation, that anyone else does: and therefore he which declares he thinks it reason to deceive those that help him, can in reason expect no other means of safety than what can be had from his own single power.