There are four parts to this section (1:12-2:17) that fall into two pairs. Solomon first related his investigations (in 1:12-15 and 2:1-11) and then gave his evaluations of each of these experiments (in 1:16-18 and 2:12-17).
Thus far Solomon had reflected on the futility of all human endeavor generally (1:3-11) and the futility of human achievement (1:12-15) and his own achievements in particular (2:1-17). Next he turned to an evaluation of labor, his own (2:18-20) as well as that of all other people (2:21-6:9).
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