 The distinction between the content and the object of a presentation rests on a psychological or epistemic difference which is, roughly speaking, the mental counterpart of Frege's distinction between sense and reference. The object of a presentation, says Twardowski using Zimmermann's terminology, is that which is presented in a presentation; the content is that through which the object is presented. An important argument Twardowski gives in favor of this distinction—and which strengthens the analogy with Frege's distinction—is that we can present the same object in two different ways by having two presentations with the same object but with different content. Twardowski calls such presentations interchangeable presentations (Wechselvorstellungen). The presentation of the Roman Juvavum and the presentation of the birthplace of Mozart have the same object, Salzburg; however, their content differs. To offer a rough analogy, think of an arrow pointing at an object: the object is what the arrow is pointing at, the content is what in the arrow makes it the arrow it is, that is, its being directed to that object and not to another. The act is just the ‘being directed towards’ of the arrow. Interchangeable presentations are like two arrows pointing at the same object.