" My definition of success is attained through self- satisfaction in knowing that you made the effort to do the best of which you are capable."

Peace of mind.

Explanation:

Peace of mind happens when a person has no worries, fears or think about anything that can cause him unhappiness.

A person that has peace of mind will always enjoy calmness, freedom, joy and happiness from within.

Therefore the definition of success is PEACE OF MIND attained through self- satisfaction in knowing that you made the effort to do the best of which you are capable because a successful person is someone who's mind is at peace , he doesn't have to worry about tomorrow or about what to do or what not to do and the person joy we have no bounds because he has mental and emotional calmness and all round peace and happiness.

can you explain it better

i believe the answer is:   psychological  experiment

in this experiment, wilhelm wundt became the first person that implement scientific method in analyzing the pyschological phenomenon.

due to this result, wilhelm wundt also able to make psychology to be acknowledged as a separate scientific field from biology.