What is the difference between metaphysical realism and naïve (or direct) realism?

Question

Metaphysical realism:

According to Wikipedia,

Metaphysical realism maintains that "whatever exists does so, and has the properties and relations it does, independently of deriving its existence or nature from being thought of or experienced.

According to SEP,

According to metaphysical realism, the world is as it is independent of how humans or other inquiring agents take it to be. The objects the world contains, together with their properties and the relations they enter into, fix the world’s nature and these objects [together with the properties they have and the relations they enter into] exist independently of our ability to discover they do. Unless this is so, metaphysical realists argue, none of our beliefs about our world could be objectively true since true beliefs tell us how things are and beliefs are objective when true or false independently of what anyone might think.

Many philosophers believe metaphysical realism is just plain common sense. Others believe it to be a direct implication of modern science, which paints humans as fallible creatures adrift in an inhospitable world not of their making.

Naïve (or direct) realism

According to Wikipedia,

Naïve realism, also known as direct realism, is a philosophy of mind rooted in a common sense theory of perception that claims that the senses provide us with direct awareness of the external world. In contrast, some forms of idealism assert that no world exists apart from mind-dependent ideas and some forms of skepticism say we cannot trust our senses. The naïve realist view is that objects have properties, such as texture, smell, taste and colour, that are usually perceived absolutely correctly. We perceive them as they really are.

Are metaphysical realism and direct (or naïve) realism the same thing?

Answer 1

The relationship between metaphysical realism and direct realism is like that between rectangles and squares, or fruit and apples. All squares are rectangles, but not all rectangles are squares. All apples are fruit, but not all fruit are apples. Everyone who accepts direct realism accepts metaphysical realism, but not everyone who accept metaphysical realism accepts direct realism.

Metaphysical realism refers to a collection of beliefs that have similarities. Direct realism is one of these beliefs, but not the only one. The other significant belief is indirect realism. You can think of it like this:

Metaphysical realism = the belief that reality exist independent of any observer
Direct realism = Metaphysical realism + the belief that our senses tell us about reality
Indirect realism = Metaphysical realism + the belief that our senses create a representation of reality

Answer 2

All the difference is that the things that really exist as base reality in the metaphysical plane (metaphysical realism) are not necessarily those things that we naively/directly think are the things that really exist as base reality. Think of the simulation hypothesis (popularised by the movie The Matrix) and the difference becomes obvious. Naive/direct realism is metaphysical realism, but not all metaphysical realism is naive or direct.