How about photons? If they are real can they be particles as well as waves? Feynman (who got a nobel prize for it together with Sin-Itiro Tomonaga and Julian Schwinger (they all thought of it independently)) went for waves. So did he think that for a photon to exist at all it needs to be classified? I think he felt photons were "real" but kind of shady before he nailed them down as waves instead of particles (making them "really real").
I remembered it the wrong way around. Feynman (and the other 2) went for particles rather than waves. What I was trying to say is that similar to atomic therory moving from "a useful pedagogical device" (1860) to "atoms really exist" (today), photons went from "this curious thing that looks like a particle or a wave depending on how you set up your experiment" to "It is a particle".