Feyerabend means by 'anything goes'

Instrumentalism

Instrumentalism views scientific theories as useful tools, not as descriptions of unobservable reality

Nominalism

Nominalism claims only particular things exist, universals are just names

The Crisis of European Sciences and Transcendental Phenomenology

Husserl's crisis argued that positivism neglected the lifeworld's meaning-giving role

Wittgenstein's later philosophy argues

Wittgenstein's later philosophy posits: "Meaning is use, not reference."

Scientific realism

Scientific realism posits unobservable entities have the same ontological status as observables

Two Dogmas of Empiricism

Quine's essay attacked two central aspects of logical positivism