Logical Vs Experiential Structure

Halliday & Matthiessen (1999: 520): 

… the logical system, within the ideational metafunction, engenders a different type of linguistic structure from that of the experiential system. In the logical world, the parts are not constituents of an organic configuration, like the process, participants and circumstances of the clause. They are elements standing to each other in a potentially iterative relationship; and each element represents an entire process.