Psychological egoism/Talk

Whether one ought or ought not be motivated by self interest may be dependent on how well one takes into account the "big picture." The "big picture" tends to include consciousness of factors which interconnect the survival potential of all people and ultimately all living things, which further depend for their survival on the health of the planet as a whole. So- if one is able to envision man as dependent on the success of other life forms and life forms in general as dependent on the health of the planet, then, at least within the limited sphere of the earth, one's self-interest will always be served by doing the best for the most.