Halliday & Matthiessen (1999: 243):
… it seems that meaning-making by transcategorising has evolved, through intermediate stages, into meaning-making by metaphorising; there is no sharp line between deriving a thing from a process, as ‘one who makes’, ‘that which is made’, and construing a process as a thing ‘making, creation’; with ‘action of making, act of making’ somewhere in between.