IV.
If I were a dead leaf thou mightest bear;
If I were a swift cloud to fly with thee;
A wave to pant beneath thy power, and share
The impulse of thy strength, only less free
Than thou, O Uncontrollable!If even
I were as in my boyhood, and could be
The comrade of thy wanderings over Heaven,
As then, when to outstrip thy skiey speed
Scarce seemed a vision; I would ne'er have striven
As thus with thee in prayer in my sore need.
Oh! lift me as a wave, a leaf, a cloud!
I fall upon the thorns of life! I bleed!
A heavy weight of hours has chained and bowed
One too like thee: tameless, and swift, and proud.
V.
This line offers an interesting juxtaposition between life, death, upsides of nature, and downsides of nature. “Thorns of life” is quite a muddled statement, especially in the context of Romanticism. Thorns are often regarded as the dark sides of beautiful flowers. Calling them the thorns “of life” gives them a special dualistic property that extends beyond their normal definition the connotations with which they come. 
 Shelley surrenders to the greatness of nature and accepts that he has no power over the unforgiving events of the world. He welcomes the storm of life and submits to it such that he may also be torn apart and recreated in a new form like a wave, leaf or cloud. 
 The final exclamatory statement, ‘I bleed’, now overtakes the invocation ‘O hear’ in the previous sections. The speaker is addressing his own troubled soul rather than the deity of the West Wind. 
 Bleeding from thorns could be a reference to the sacrifice of Jesus and submitting to a higher power in order to achieve a new era of brightness and peace. Here, nature is the divine power providing freedom from the pains of human life.
Ode to the West Wind