The acquisition of ideas is a gradual process, of course.
Everything begins, then, with simple ideas of.
But it is not uncommon to see the claim that Kant actually denied this, and it is Kant, not Hume, who is typically belabored for implicitly prohibiting the development of non-Euclidean systems.
The visual and tactile ideas of the globe are distinct.
After Ryle, philosophers sought a more explicit and generallynaturalistic ontology of mind. In the 1950s materialism was arguedanew, urging that mental states are identical with states of thecentral nervous system. The classical identity theory holds that eachtoken mental state (in a particular person’s mind at a particular time)is identical with a token brain state (in that person’s brain at thattime). A stronger materialism holds, instead, that each type of mentalstate is identical with a type of brain state. But materialism does notfit comfortably with phenomenology. For it is not obvious how consciousmental states as we experience them—sensations, thoughts,emotions—can simply be the complex neural states that somehowsubserve or implement them. If mental states and neural states aresimply identical, in token or in type, where in our scientific theoryof mind does the phenomenology occur—is it not simply replacedby neuroscience? And yet experience is part of what is to be explainedby neuroscience.