Empirical versus theoretical existence and truth

On the basis of an analysis of everyday experience and practice, criteria o f legitimate assertions of existence and truth are offered. A specific obje ct, like a newspaper, can be asserted to exist id it has some invariant cha racteristics and is present in actual perception. A statement, like "this n ewspaper is black and white" can be accepted as true if it is well-establis hed in some empirical domain. Each of these criteria provides a sufficient condition for acceptance of existence and truth, respectively, at the empir ical level. following Herman weyl, it is argued that these criteria can be extended to the scientific theoretical level to support a selective and mod erate version of scientific realism according to which entities like the el ectromagnetic and gravitational fields, but not crystalline spheres or some topological manifolds, can legitimately be asserted to exist.