Moby Dick pg 13

"but that same image, we ourselves see in all rivers and oceans. I is the image of the ungraspable phantom of life; and this is the key to it all."

States one main theme of the book, water/ocean connects everything. Many believe that life evolved from water and moved to land over time. This quote gives the idea of seeing oneself in water much like it is a part of us; and that water "is the key to it all" or life.