The KISS Grammar Workbooks Back to Prompts
From Loren Eiseley's 
The Unexpected Universe
N.Y.: Harcourt, Brace & World, 1969. 181-182.

     It is man's folly, as it is perhaps a sign of his spiritual aspirations, that he

is forever scrutinizing and redefining himself. A mole, so far as we can

determine, is content with its dim world below the grass roots, a snow 

leopard with being what he is -- a drifting ghost in a blizzard. Man, by 

contrast, is marked by a restless inner eye, which, in periods of social 

violence, such as characterize our age, grows clouded with anxiety.

     High school is normally a time when most students are seeking a sense of their own identity, so they may find this an interesting prompt for a writing exercise. Having the students analyze and discuss the syntax (as well as the content) of this passage before they write about it may be particularly important. Many students may be confused by the ellipsis and the noun appositive ("ghost")  to a subordinate clause that functions as the object of a preposition.

Analysis Key
(Code and Color Key)

     It is man's folly (PN), [Adv. to "is" as it is perhaps a sign (PN) {of his 

spiritual aspirations}], [Del. Subj. that he is forever scrutinizing and redefining

himself (DO)]. | A mole, so far [Adv. to "so" as we can determine], is 

content (PA) {with its dim world} {below the grass roots}, | [#1] a snow leopard 

*is content (PA)* {with being [#2] [PN of "being" what (PN) he is] -- a drifting

ghost [#2] {in a blizzard.}} | Man, {by contrast}, is marked (P) {by a restless inner 

eye}, [Adj. to "eye" which, {in periods} {of social violence}, {such as *those} [#3] 

[Adj. to "those" that* characterize our age (DO)], grows [#4] clouded (PA)

{with anxiety}]. |

1. Technically, this is a comma-splice, but it clearly makes sense here as "snow leopard" is easily related to the previous subject ("mole"), and the comma prepares, more or less, the reader for the following ellipsis of "is content." Most grammar textbooks, by the way, suggest that this comma should be a semicolon and that a comma should replace the ellipsed verb -- "below the grass roots; a snow leopard, with being ...." I personally am not about to tell Eiseley that he made a mistake.
2. The gerund "being" is the object of the preposition "with." The "what he is" clause is a predicate noun after "being." "Ghost" is an appositive to the "what he is" clause.
3. The "such" phrase modifies "periods."
4. This "grows" is very close to "becomes," and thus this verb is very close to passive voice. As to whether or not it should be so considered is, I'm sure, a matter of dispute among grammarians. Within the KISS framework, it can be explained either way.