  On the basis of what I call physico-formalist philosophy of mathematics, I
will develop an amended account of the Kantian--Reichenbachian conception of
constitutive a priori. It will be shown that the features (attributes,
qualities, properties) attributed to a real object are not possessed by the
object as a "thing-in-itself"; they require a physical theory by means of which
these features are constituted. It will be seen that the existence of such a
physical theory implies that a physical object can possess a property only if
other contingently existing physical objects exist; therefore, the
intrinsic--extrinsic distinction is flawed.
