Attacking Locke’s Distinction Between Primary and Secondary Qualities
Berkeley’s Conceivability Argument is very important because, by accepting it, you essentially agree that there is no external objective reality that we can conceive of.
If x is possible then x is conceivable.
The primary properties of an object are inconceivable when abstracted from the secondary properties.
C. It is not possible for primary and secondary properties to be distinct.
Cannot Conceive of the Unconceived
The redefined definitions in Locke’s Primary & Secondary Quality Distinction do not manage to escape all of Berkeley’s criticisms. The problem remains that primary properties of objects are intrinsic and therefore independent of perspective. To conceive of such properties, Berkeley argues, is impossible because to ‘conceive of something as existing unconceived is…misguided.’ [Grayling 1986, 38] and would require us to have a view from nowhere.
In more specific terms, Berkeley argued that one cannot conceive of an extended object without also giving it some colour. Similarly one cannot conceive of an object’s shape without viewing it from some angle or other (which immediately makes it relational). Therefore, by (1), conceiving of objects’ primary properties without their secondary properties is impossible and, as a result, the primary/secondary distinction is flawed.
Criticising Berkeley’s Conceivability Argument
The problem with Berkeley’s Conceivability argument is the second premise, because the fact that no one can imagine what a perspective independent world would look like does not mean that no one cannot conceive of it – it is possible to conceive of objects’ primary properties in a mathematical sense.
This idea is supported because mathematicians can conceive of twelve dimensions in our Universe; for example in scientific theories such as String Theory. The size of an atom is far too small to be conceived of through our senses. The fact that these things are still considered possible shows that a purely mathematical conception of properties is enough to consider them conceivable.
Further, in Berkeley’s Argument from Relativity, it has already been shown that number (including measurements) is intrinsic to objects. As a result it is possible to conceive of primary properties abstracted from secondary properties. For example “if this ball was unconceived then it would be ‘a three dimensional surface, all points of which are equidistant from a fixed point,’ [www.answers.com/topic/sphere] with a radius of five centimetres” is conceiving of an object’s primary properties. Even though this example is not a comprehensive conception (it lacks solidity and motion) I have no doubt that a mathematician could conceive of all of these properties through number.