 An intuition is for Bolzano an idea that is simple and singular (cf. section 3.5). The question arises immediately whether such an intuition exists after all and — if so — what it can contribute to epistemology. Both questions are answered by Bolzano at once: In order to show that there are intuitions, he hints at subjective ideas (ideas in our minds) that grasp “objective” intuitions as defined before; and since these subjective intuitions exist in our actual world, the corresponding “objective” intuitions must exist (in the sense of ‘es gibt’) in the logical realm of World 3. What are the examples of subjective intuitions, however, that Bolzano can put forward in support of his claim? It is subjective ideas such as the subjective idea of the change in our mind that is the immediate reaction on an outer object (such as a rose) that stimulates our senses. In everyday language we usually express such an idea only by the word ‘that’ (‘dieses’ or — in Bolzano’s old-fashioned orthography — ‘dieß’). Bolzano’s rather long-winded explication (in WL I, 326 f.) reveals subjective ideas of a particular sensation or sense-datum as his favorite examples of subjective intuitions (cf. also WL III, 21 f.). The object and the cause of a subjective intuition of this kind is itself a mental phenomenon such as a subjective idea or a judgment (WL III, 85). If a subjective intuition is directly caused by an “outer” object, Bolzano calls it an ‘outer intuition’. Also in the case of an outer intuition, its proper object is not the “outer” cause of it but an “inner” mental event; human beings are capable only of having subjective intuitions whose proper object is a change in their mind (WL III, 89). In other passages Bolzano seems to be less cautious and claims also of an idea such as [Vesuvius] (WL II, 38) or [Socrates] (WL I, 346, in explicit contradiction to WL III, 89) to be a pure intuition whose appearance in the mind of a thinking being is a subjective intuition. This would obviously result in taking each rigid designator (in today’s terminology) to express an intuition.