Abstract
The notion of 'truth in itself' was crucial for Bolzano, it is the entrance to his philosophy. Bolzano had usually his notions carefully constructed and perfectly justified; nevertheless the notion of 'truths in themselves' or 'objective truths' is the one of the most difficulty grasped. Bozano?s aim was to prove their existence by the independent logical definition.
Although he referred to the scholastic tradition he did not need God as a guarantee of their existence. The same special statuses of existence have 'sets'.
Bolzano?s mathematical theory of infinity was based on the proof of the existence of the infinite set of 'truths in themselves'