Our current best model of ultimate reality is probably quantum fields in a Fock space. But since our knowledge of reality is limited by our sensory access* can we really generate adequate models? (See my blog of 27 April 2017.) Bohr believed we would have to stick to classical concepts and language only. Things like mass, force, 3 space, time, etc. The fact that we have been able to create mathematics that has no application (examples) in the physical world may argue that we CAN extrapolate to pattern structures that transcend classical (direct sensory based) models.
* We have only our 5 senses: touch, smell, taste, sight, and hearing but other creatures can also directly sense electric and magnetic fields.