For if some moderns have thought to enlarge it by interpolating psychologi cal chapters about our different cognitive powers (about imagination, wit), or metaphysical chapters about the origin of cognition or the dif ferent kinds of certainty in accordance with the diversity of objects' (about idealism, skepticism, etc.), or anthropological chapters about our prejudice (about their causes and remedies), then this proceeds only from their ignorance of the peculiar nature of this science.