 These considerations motivate the algebraic point of view that algebras of observables rather than observables themselves in a particular representation should be taken as the basic entities in the mathematical description of QFT, so that the above-mentioned problems are to some degree avoided from the outset. However, obviously this cannot just be the end of the story. Even if UIRs are not basic, it is still necessary to say what the availability of different UIRs means, physically and thereby ontologically.