In this poem, Doors of Daring by Henry van Dyke describes how people imprison themselves in their own lack of confidence. He uses extensive use of symbolism to show that people should explore life and not be discouraged. Living life to its fullest is the main theme in Dyke's poem. In three particular lines, he proves this theme.

One line near the end of the second paragraph states "Push out, set sail, explore!" The author uses this line to tell people that they should explore life in many ways. Dyke obviously believes in exploration and adventure. He believes that exploring life in new ways is the key to living life. Trying new things is the major element in living life

In another line in the third paragraph states "The bars of life at which we fret, that seem to prison and control." Dyke is clearly using this line to illustrate how people can imprison themselves in their own mind with worries and fears. This means that people lose self-esteem because of their fears of not succeeding. Many people worry about trivial things and need to let them go to live life. Dyke feels people break through their personal prison.

One important line in the last paragraph states "Say not, "too poor," but freely give; Sigh not, "Too weak," but boldly try." Dyke uses this line to tell people that they must at least give an attempt to anything they do. The line say not too weak but try, is stating that an attempt ahs to be made before giving up. Never give up without trying is the point that Dyke is trying to get across to readers.

The main theme that Henry van Dyke is stating is for people to explore and try different things. Exploring life is the only way to live life to its fullest. With mental prisons, people must break free of them and try new things. With these lessons, humanity can achieve many goals and have a higher self-esteem.