sentences:  In Book 1, Part 4 of A Treatise of Human Nature, he argues that we have no impressions of primary qualities at all, but rather only various impressions that we tend to group together into some particular mind-independent quality.Thus, according to Hume, primary qualities collapse into secondary qualities, making the distinction far less helpful than it first might have seemed.Immanuel Kant, in his "Prolegomena to Any Future Metaphysics That Will Be Able to Present Itself as a Science", claimed that primary, as well as secondary, qualities are subjective.