Dualism
Dualism says reality has two basic kinds of thing. In philosophy of mind, those two kinds are usually mind and body. The mind is thought, feeling, and awareness. The body is matter that physics can describe.
Substance dualism makes the stronger claim. It treats mind and body as two different substances. René Descartes gave the classic version. He argued that he could doubt his body but not his thinking. Therefore, thinking seemed to belong to a non-physical substance.
Property dualism is milder. It allows one kind of substance, often the physical brain. Even so, it says some properties of that brain are not physical. Pain, colour experience, and inner awareness would be examples. They would depend on the brain but not reduce to brain talk.
Dualism tries to explain a familiar gap. A scan can show neurons firing. It does not seem to show what it is like to taste tea or feel fear. Supporters say this inner side is real. They also say a complete physical list still leaves it out.
Critics press the interaction problem. If the mind is not physical, how does it move the body? A decision appears to raise an arm. That looks like a physical effect. Dualists must then explain the link without breaking the closed picture of physical causes. Some appeal to a special point of contact. Others say the link is real but not like ordinary pushing and pulling.
Science adds pressure. Brain damage changes speech, memory, and personality. Drugs change mood. These facts fit a close dependence of mind on brain. Physicalists say that dependence is evidence that mind is not a separate substance. Dualists reply that dependence does not prove identity. A radio depends on its parts, they say, yet the signal is not the same as the case.
Other views reject the split. Physicalism says only physical things exist. Idealism says mind comes first. Neutral monism says both mind and matter come from one more basic kind. Each camp still has to explain experience, cause, and personal identity.
Dualism remains useful as a clear position. It forces a choice about what a person is. It also keeps the question open: is awareness only brain activity, or is something more at work? The debate continues because both the inner view and the scientific view feel hard to dismiss.