Just so far then as there are certain things which the state cannot do, or by doing which it lessens its power, so far there are things which it has no 'right' to do. 34. Spinoza proceeds to consider the relation of states or sovereign powers to each other. Here the principle is simple. They are to each other as individuals in the state of nature, except that they will not be subject to the same weaknesses. 'Nam quandoquidem (per art. 2 hujus cap.) jus summae potestatis nihil est praeter ipsum naturae jus, sequitur duo imperia ad invicem sese habere, ut duo homines in statu naturali, excepto hoc, quod civitas sibi cavere potest, ne ab alia opprimatur, quod homo in statu naturali non potest, nimirum qui quotidie somno, saepe morbo aut animi aegritudine, et tandem senectute gravatur, et prater haec aliis incommodis est obnoxius, a quibus civitas securam se reddere potest' (III. 11). In other words, '... duae civitates natura hostes sunt. Homines enim in statu naturali hostes sunt. Qui igitur jus naturae extra civitatem retinent, hostes manent' (III. 13). The 'jura belli' are simply the powers of any one state to attack or defend itself against another. The 'jura pacis,' on the other hand, do not appertain to any single state, but arise out of the agreement of two at least. They last as long as the agreement, the 'foedus,' lasts; and this lasts as long as the fear or hope, which led to its being made, continues to be shared by the states which made it. As soon as this ceases to be the case, the agreement is necessarily at an end, 'nec dici potest, quod dolo vel perfidia agat, propterea quod fidem solvit, simulatque metus vel spei causa sublata est, quia haec conditio unicuique contrahentium aequalis fuit, ut scilicet quae prima extra metum esse potest, sui juris esset, eoque ex sui animi sententia uteretur, et praeterea quia nemo in futurum contrahit nisi positis prsecedentibus circumstantiis' (III. 14).