Property Dualism finds it critically important to distinguish between two categorically different properties. There are causal properties, and there are phenomenal properties. As David Chalmers says, phenomenal qualities are "Part of the basic furniture of nature, just as the laws of physics are." so all properties, phenomenal and causal are physical. The classic example of a causal property is a property of a "red" strawberry when it reflects 650 NM light. At the other end of the perception process, is our knowledge of the strawberry, or neural correlate of such, and this is what has a redness quale or property that is categorically different from any causal property.
We can detect all causal properties via traditional cause and effect based senses and scientific instruments. Qualia or phenomenal properties are very different from causal properties in many ways. They are 'ineffable' or suffer from the "quale interpretation problem" (described in the Representational Qualia Theory
camp). If a neural correlate in our brain, possibly something like glutamate, is what has the redness quale we experience, and if it has a causal property such that it reflects white light, and if we interpret such as having a whiteness property because of this, this would be a classic example of incorrectly interpreting what glutamate's fundamental or phenomenal property was, or what it is phenomenally like, or how it could be experienced.
Some people believe qualia can 'arise' from or be entirely described by only abstract representations or software. Unless someone adds in some additional physical magic, which ties a quale to a particular abstract representation in some 'hard' way, we believe they either don't fully understand what a phenomenal property is, or are using a very different definition of the term qualia, than what we use. By definition, abstract knowledge, like ones and zeros, don't matter what they are represented by, as long as the underlying hardware properly interprets it as the ones or zeros the properties represent. In other words, we define qualia to be that which cannot be communicated by abstract information alone, without knowing how to properly interpret the representations. You cannot know what the abstract word 'red' means, phenomenally, unless you include some additional qualification like "my redness". After all, my redness could be more like your greenness, or possibly like something you have never experienced before.
There are different types of property dualists. David Chalmers is probably the most famous property dualists and argues that phenomenal properties, in some 'hard' way, 'arise from any functional equivalent organization, from neurons to silicon transistors. This version of property dualism is currently the most well accepted, and is represented by the Functional Property Dualism
sub camp. Recent gains in a competing camp that might be on the verge of taking the lead is very different in that it predicts that there is some neural correlate, or material substance that simply has the phenomenal properties our brains use to represent conscious knowledge with. Without the right stuff, you can't have the same quale. This theory is represented by the Material Property Dualism
sub camp. If Material Property Dualism is effingly demonstrated to be true by science, it will falsify any theory or possibility that we might be in an abstracting simulation.
Property dualism is a very broad theory that includes most all "spiritual" models. These include Higher Dimensional theories
. This super camp includes the Calibi-Yau-Ruquist hypothesis
and the Smythies-Carr Hypothesis
sub camps. The latter was first proposed by C.D. Broad, and currently supported by John Smythies
and Bernard Carr. This theory predicts phenomenal properties exist in the branes of string theory, or in some higher dimensions. Property Dualism also includes many traditional or religious 'spiritual' views of consciousness that places the phenomenal properties in some 'spiritual', or non physical domain or dimension.