What is a principled person?
I define it as a person who lives by certain rules no matter how much they affect the chances of his superior survival. And whose actions aren't based primarily with the motive of superior survival.
Both the hero in 3 Idiots (also the hero in DDLJ when he explains to his future mother-in-law about two options in life) and the mythical King Harischandra eschewed running after survival, instead they chose to follow their own values at least at a point in their life, if not in their life.
All animals focus primarily on survival (eating and procreation and avoiding death). The concept of principle is largely unimportant to them.
Human beings, somewhere along the way, invented the concept of principles, things that would curb incidental individual freedom or chance of survival but what we thought would be good for society as a whole.
One might think that all of us have principles. Not really is my answer. Go back to the definition above. That kind of principles is lacking in most of us.
Yes, each of us has principles in varying extent.
The most famous example of a very unprincipled human being, a person who solely lives for superior survival, is the current American president.
It does seem like principled living does not increase the chance of survival except, of course as depicted in the fictional examples given above.
Extrapolating the logic, does it mean that every person who doesn't survive will is in a way principled?
Sounds awful. What's the issue?