|Modalities: modalities are in modal logic possibility, necessity and contingency.|
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NominalismVsmodality - EmpiricismVsmodality - solution today: instead probability - Hermann Weyl
Modality / Science / Fraassen: in science appears modality only insofar as its language is modal - a we must also consider the structure of language here together with the models and actual phenomena.
Possible Worlds / Fraassen: but we must not regard them as real.
modal / actual / Wittgenstein / Fraassen: a) actual: nothing that is green is red - b) modal: there is no possible object that is both green and red - this goes beyond the first by saying something about what could not be - a) says that there is no point in the color spectrum that is green and red - b) that absolutely no point of the spectrum is so.
B. van Fraassen
The Scientific Image Oxford 1980