The poem uses caesura in six lines to reflect both its subject matter and the speaker’s state of mind. These caesuras fall into two categories: hard and soft. Those aren’t technical terms. In this poem, we're using hard basically means an abrupt stop caused by a period, semicolon, or exclamation mark. We're using soft to mean a stop caused by a comma.
In line 1, a semicolon separates the opening statement from an elaboration on that statement. The opening statement expresses a problem: that human beings spend too much time in the manmade, industrial world. Immediately after this, the speaker gives examples of the effect that this problem has on the average city dweller: “late and soon, / Getting and spending, we lay waste our powers.” Arguably, however, the caesura itself is the first example of people’s unhealthy attachment to the fast-paced material world. Consumed by a fast-pace lifestyle, the speaker rushes headlong into “late and soon.”
Line 9 contains the other instance (actually, two instances) of a “hard” caesura. Nestled between a period and exclamation mark is the apostrophe, “Great God!,” which marks the border between the octave (the sonnet's first eight lines) and the sestet (the sonnet's final six lines). As in line 1, this disjointed line reflects the speaker’s scattered mindset. The period after "Moves us not" also emphasizes the finality of that statement.
In lines 2, 4, 8, and 11, commas break the flow of words. Less a reflection of the feelings of the speaker, these caesuras give the poem a dramatic effect. In line 8, for example, commas separate out “for everything” in order to linger on the cost humankind’s pursuit of material gain. In line 11, the caesura accommodates a specification of the speaker’s location, a “pleasant lea.”