This book has been finished at the Institute of Philosophy of Slovak Academy of Sciences. Here, my gratitude goes to members of the Logic, Epistemology and Metaphysics of Fiction band. Namely, I thank to D. Glavaničová, M. Kosterec, N. Osorio Kupferblum, M. Pascucci, M. Sambrota, D. Zeman an M. Zouhar.