The philosophy of David Hume was one of the most important inspirations for the majority of the Brentano School representatives. Their great engagement in the philosophical dialogue with Hume’s views ought to be reflected on the plane of ethical deliberations as well. Though this influence did not manifest itself expressis verbis, quite an explicit bias can be found in Brentano and his pupils’ ethics, the sources of which ought to be sought in Hume inspirations. It is expressed as a thesis, that the requirement of the reduction of tension between the subjective state of the subject and the objective state o f things is the source of moral obligation. The paper shows how this thesis can be derived from Hume’s concept and illustrates, with a...