Analyze the following passage for audience, purpose, tone, and perspective to show the theme.
"Thus absolutely lost in thought, and dying with the very thoughts of drowning, I come up with the post, who I did not see 'til very deliberately a few paces, when we entered a thicket of trees and shrubs, and I perceived by the horse's going, we were on the decent of a hill, which, as we come nearer the button, 'twas totally dark with the trees that surrounded it. But I knew by the going of the horse we had entered the water, which my guide told me was the hazardous river he had told me of; and he, riding up close to my side, bid me not fear-we should be over immediately. I now rallied all the courage I was mistress of, knowing that I must either venture my fate of drowning , or be left like the children in the wood. So, as the post bid me, I gave reins to my nag; and sitting as steady as just before in the canoe, in a few minutes got safe to the other side, which he told me was the Narragansett country." (Sarah Kemble Knight, The Private Journal)