Black and white are perceived as colours. Yet the assertion that they are opposed is a relation, not merely a colour-image. The objection therefore asks: if opposition is intelligible, why classify this illustration under an estimative link?
We must distinguish the universal relation of contrariety studied by logic from the immediate contrast evoked by particular black and white objects in a listener's mind. The same terms can be analysed at different levels; the taxonomic question is about which connection motivates the utterance.