Halliday & Matthiessen (1999: 131):
Saying is construed as proceeding from Sayer to Receiver (she asked/told/commanded him — 'she addressed him'). In contrast, sensing embodies two complementary perspectives: either the Senser's involvement in the sensing ranges over the Phenomenon or the Phenomenon is construed as impacting on the Senser's consciousness (she likes the design : the design pleases her).