TiborZ Koos 6 July 2023

Kastrup repeatedly claims that physics only deal with quantities not qualities.
Is the equation F=ma merely a relation between 7 numbers ? Consider the 3D acceleration vector. Mathematically this is represented with an ordered set of 3 numbers, corresponding to x, y, z coordinates. The same representation could of course be used for example for the state of the economy if we consider unemployment, GDP growth, and interest rates as dimensions of a vector. Is the acceleration vector the same kind of thing as the "economy vector"? The obvious difference between the 2 is crucially related to a mode fundamental one. Acceleration is a geometrical vector and inherits the intrinsic properties of space. That means for example that the meaning of the length of the vector remains the same if we translate the vector from one location to the another or if we rotate it in . While we can calculate the "length" of the economy vector the same way as the acceleration vector, whatever the former may capture about the state of the economy is not invariant to translation or rotation. Likewise there is no economic meaning of "rotating" this vector. Thus, a physical vector is much more than its mathematical representation, the 3 numbers, the 3 quantities: the 3 numbers come with a very specific interpretation of what they mean, namely the intrinsic properties or rules of Euclidean geometry. These rules or properties are clearly not quantities: symmetry of 2 objects does not require any specific numerical values (size, location) to be applicable. Thus, even the seemingly most purely "quantitative" component of a a physical law is more than a number, that is more than a quantity. 1 m and 1F do not mean the same thing even thought they have the same quantitative value (1). So what should we call the "dimensions", the "m" and "F" part ? The obvious answer is that they are what we call qualities. Mass "does" different things than temperature regardless of what value they happen to take.
This notion or quality applies equally to "mental qualities". The "redness of the red" is indeed more than a quantity but that does not turn it into some magic substance as Kastrup portrays it in his fairy tale. When we use introspection to check if color or other qualia are quantities or qualities our minds compute the latter result, because these are indeed dimensions and not particular quantities along a specific dimension. The fact that introspection does not have complete access to the entire process of how these dimensions are used is nothing surprising. We also have no access to the process of perception, or motor planning. But this does not make qualia some magic blue light the flickers at the bottom of reality. Kastrup's story is not a even mental version of vitalism, it is pure science fiction.

David Simpson 11 February 2021

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Jeffrey Anderson 12 July 2020

Physicalism is the belief system of Artificial Intelligence..... we must cling to notions of inner consciousness and unpredictability like all life itself depends on it...as it does!