What Plato's theory of Forms claims — abstract perfect Forms are more real than physical copies

What modal realism claims — possible worlds are as real as the actual world (David Lewis)

Modal realism posits all possible worlds have equal reality to our own

What instrumentalism claims — theories are useful tools, not descriptions of unobservable reality

Instrumentalism views theories as practical tools, not literal depictions of unobservable phenomena

What substance dualism claims — mind and body are fundamentally different kinds of stuff

Dualism posits that mind and body are distinct, non-physical and physical substances, respectively

What epiphenomenalism claims — consciousness exists but has no causal power over the physical

Epiphenomenalism: Consciousness is a byproduct, causally inert to physical processes

What Merleau-Ponty's embodied phenomenology argues — perception is bodily, not mental representation

Perception is inherently embodied, not merely mental constructs

What the problem of universals asks — do abstract properties (redness, roundness) exist independently

Universals question: Do abstract properties like redness exist independently of particular objects?