Can you imagine the kind of similarity that exists between a ship and human being? Here are some of them.....
(1) All the major machineries- Human mind.
All the machineries of a ship should be in good working condition for the successful operation of the ship. So should be human mind. If mind fails, the story ends. Mind defines the innate characteristics (in other words, nature) of a human being.
(2) Major pipelines- The emotions linked with various thought process.
Each of the pipelines has its own distinct role to play in the ships operation. Similarly there exists the minds role to allocate the correct emotion to the particular thought process. This provides the broad definition of human personality.
(3) Small, connecting pipelines that connect the major pipelines - Minds efforts to link distinct thoughts and conclude the effects.
These small pipelines which connect the major ones are no less important than the major pipelines. Similarly the connection our mind creates between two distinct emotions reflects the depth of human personality to a great extent. Imagine correlating two things which happened today and try to go deep into the process. Extend this approach as broad as you can.
(4) Valves - The mind's control device which decides what and when to blurt out the internal happenings to the exterior world.
Valves, when malfunction lead to disastrous results. Similarly the mind should have a good knowledge on what should be allowed to flow to the exterior world and when to close its valve. This reflects the effectiveness of the human personality.