Monism is the idea that all of reality is, at its deepest level, one unified whole. Instead of thinking the universe is built from two fundamentally different kinds of things, monism says there is one basic kind of reality underneath everything we experience. The differences we notice, such as mind and body, people and nature, matter and energy, are seen as expressions, forms, or perspectives of that single underlying unity.

The core claim

Monism answers a simple question: how many ultimate “building blocks” does reality have?

• Monism: one
• Dualism: two (commonly mind and matter)
• Pluralism: many (multiple kinds of fundamental stuff)

So a monist might say the world is not divided into separate realms. There is not a “mental world” over here and a “physical world” over there. There is one reality, and everything fits inside it.

Common types of monism

Monism comes in different versions, depending on what someone thinks the one reality is like.

Substance monism

This is the most straightforward form. It says there is one fundamental substance, one basic kind of “stuff,” and everything is made from it.

• Materialist or physicalist monism: everything is ultimately physical. Minds, thoughts, and emotions are real, but they are what physical processes look like from the inside, like brain activity experienced as awareness.
• Idealist monism: everything is ultimately mental or experiential. Matter is not denied, but it is interpreted as a pattern within consciousness or mind.
• Neutral monism: the foundation is neither strictly mental nor strictly physical. Mind and matter are two ways of describing the same deeper, neutral reality.

Attribute monism

This view says there is one substance, but it can be described with different kinds of properties. Someone might accept one underlying reality while still saying mental and physical descriptions are both valid, just at different levels or from different angles.

Priority monism

This approach says the whole universe is fundamental, and the parts are less basic. Individual things exist, but they depend on the total system to be what they are, like organs depending on the body or waves depending on the ocean.

Why people are drawn to monism

Monism appeals to people because it promises simplicity and coherence. If reality is one unified thing, then it may be easier to explain how everything interacts. It can also support a sense that nothing is truly separate, that humans are not isolated from nature, and that mind is not floating outside the physical world.

In science, many people prefer explanations that reduce complexity to simpler foundations. In spirituality and mysticism, monism often resonates with experiences of unity, where boundaries between self and world feel less absolute. In philosophy, monism can be a way to avoid the puzzle of how two totally different kinds of things could ever connect.

What monism does not necessarily claim

Monism does not automatically mean that everything is the same in everyday life. It does not require you to deny differences, individuality, or change. A monist can still say that people are distinct individuals, that pain is not the same as joy, and that moral choices matter. The claim is about what is ultimately real at the deepest level, not about flattening all distinctions in daily experience.

A simple way to picture it

Imagine reality like an ocean. There are waves, currents, foam, and tides, all different and sometimes dramatically so. But they are all water. Monism says reality is like that: countless forms and patterns, one underlying whole.

The big question monism raises

If everything is one, why does it look and feel like many?

Different monist traditions answer in different ways. Some say the appearance of separateness is a useful perspective, like zooming in on details. Others say separateness is a real feature at the surface level, even if it is not ultimate. And others treat separateness as a kind of illusion created by limited perception.

Closing thought

Monism is the belief that the universe is not built from separate, disconnected realities. It is one unified whole, and everything we experience is part of that single reality, even when it appears divided.