Art. 59 BV; scope of the prohibition on summoning an established debtor before the court of another canton. The constitutional guarantee is confined to inter-cantonal relations and does not regulate the internal judicial organization of a canton. Cantonal provisions on local competence remain binding on cantonal residents, even if they deviate from the federal rule. A personal claim brought within the defendant’s own canton therefore cannot be challenged under Art. 59 BV merely because the claimant elects a particular local forum; the provision is inapplicable where only an intra-cantonal competence issue is in dispute (consid. 1-2).