 Therefore, sense perception and intellectual cognition are complementary. Even though there are intelligible things that are not sensory, all sensory things are intelligible (DOS 430–431): they are known by the senses as particulars and ordered towards further intellectual cognition (DOS 433). “Sensation is”, Kilwardby says, “the gate to human cognition”, because there can be no knowledge of universals (and demonstration) without the knowledge of particulars (NLP I.33, 509; DOS 433).