To determine the central idea of an essay on man, the reader should first FIND OUT THE SUBJECT OF THE ESSAY AND WHAT THE AUTHOR OVERALL OPINION ABOUT THE SUBJECT IS.
The central idea of an essay or text refers to the main idea in the essay; it is the point that the author is trying to pass across to his readers. Some authors clearly state the main idea of their writings while some authors do not, in this case the central idea has to be determined by inference. An essay may have more than one central ideas. Generally, the central idea of an essay can be found in three different places, which are: in the beginning of the essay, near the end of the essay or it can be implied through the sentences used in the essay.
I think it is talking about how the speaker feels about what is according during his life
