Final answer:
The theme of Emily Dickinson's poem is best expressed as the idea that emotion can be overwhelming at times, as it depicts intense emotional states metaphorically through a storm.
Step-by-step explanation:
The theme of the poem "An awful tempest mashed the air" by Emily Dickinson can best be expressed by the statement that emotion can be overwhelming at times. This is seen through the depiction of the storm as a metaphor for powerful emotions that one cannot easily escape or control. The poem conveys a sense of turmoil and intensity that can mirror the inner emotional state of a person when they are faced with overwhelming feelings.
The excerpts provided support this interpretation as they depict nature's forces and human emotions in a manner that highlights their overpowering and sometimes destructible influence. For instance, the reference to the 'tempestuous yet sternly beautiful night' and the impetuous fury of the wind relates to the intensity of emotions that one may feel. Likewise, the mention of 'evil things, in robes of sorrow' and the shepherd's contemplation of 'wicked deeds' in response to the evils of poverty and despair reinforces the idea of overwhelming emotion leading to darkness or desperation.