Immanuel Kant
1724-1804

“Justice, sir, is the great interest of man on Earth. It is the ligament which holds civilized beings and civilized nations together.”
    Daniel Webster

“Whatever is my right as a man is also the right of another; and it becomes my duty to guarantee as well as to possess.”
    Tom Paine

The principle of treating others as one would wish to be treated is well known as the “Golden Rule.” Wikipedia documents that the concept occurs in some form in nearly every religion and ethical tradition. Today in Western societies the Golden Rule is equated with our notions of justice and fair play. But historically, this is NOT what people understood as “justice.” It is important to appreciate the meaning of “justice” before the Enlightenment.
Here is an excerpt from the Wikipedia article on nobility: “Nobility is a social class, normally ranked immediately under royalty, that possesses more acknowledged privileges or eminence than most other classes in a society, membership thereof typically being hereditary...Prior to the French Revolution, European nobles typically commanded tribute in the form of entitlement to cash rents or usage taxes, labour and/or a portion of the annual crop yield from commoners or nobles of lower rank who lived or worked on the noble's manor or within his seigneurial domain...Nobles exclusively enjoyed the privilege of hunting...Peasants were not only bound to the nobility by dues and services, but the exercise of their rights was often also subject to the jurisdiction of courts and police from whose authority the actions of nobles were entirely or partially exempt.”

Consequently, “justice” historically meant giving the king and the nobility their fat share and being thankful that they left you whatever.

Then came Tom Paine and the idea of equal justice. And then came Immanuel Kant, who is regarded as the greatest moral philosopher.
Kant argued that reason is the source of morality. His principle of universalizability requires that, for an action to be permissible, it must be possible to apply it to all people equally.

Kant: “Act only according to that maxim by which you can at the same time will that it should become a universal law.”
We should treat everyone equally because arbitrary bigotry is irrational depravity.
This is simply the Golden Rule; but Kant explained why it should apply to everyone always: When we are deciding what is the right way to treat someone, every ability that differentiates people is merely part of their contingent temporary situation. For example, the judgement that you are most qualified for a job could change if a new applicant arrives or you suddenly became insane or very ill. Since we are only differentiated by contingencies, we are essentially equal! Denying Kant's perspective destroys empathy and morality!

Kant's moral perspective is actually the exact way that my parents taught me to get along with people.
When I was inconsiderate of others, my parents would ask me questions like these:
“Would you like it if someone did that to you?”
“Do you think it would be OK if everyone acted like that?”
“Do you think you are special, and the rules don't apply to you?”
“Do you think the world owes you a living?”
Naturally, in my youth, I was not a deranged theologian, so I had to answer “No.” to these questions.
This sort of enculturation is normal in modern, non-authoritarian countries that have cultures based on reason; as opposed to old fashioned cultures based on dogma and force.

“Every kindergarten teacher is implicitly a Kantian.”
    Michael Sugrue

The gist of Kant's moral philosophy is simply this. Don't be arbitrary. Be consistent. Everyone gets the same chances that you think you would deserve in the same situation.

“Give to every human being every right that you claim for yourself. It is a question of honesty.”
    Robert G. Ingersoll

Steven Pinker:
“Morality comes from a commitment to treat others as we wish to be treated, which follows from the realization that none of us is the sole occupant of the universe.”
“The more you think about and interact with other people, the more you realize that it is untenable to privilege your interests over theirs.”
“[E]quality is not the empirical claim that all groups of humans are interchangeable; it is the moral principle that individuals should not be judged or constrained by the average properties of their group. ...If we recognize this principle, no one has to spin myths about the indistinguishability of the sexes to justify equality.”
“Morality...is a consequence of the interchangeability of perspectives and the opportunity the world provides for positive-sum games.”
“Reading is a technology for perspective-taking. When someone else's thoughts are in your head, you are observing the world from that person's vantage point...”
“If you aren't just brought up in your tribe but interact with other people either directly or vicariously, through journalism and literature, you see what life is like from other points of view and are less likely to demonize them or dehumanize others and more likely to empathize with them...”
“'Capitalism' is a dirty word for many intellectuals, but there are a number of studies showing that open economies and free trade are negatively correlated with genocide and war.”
“Anything that makes it easier to imagine trading places with someone else increases your moral consideration for that other person....Commerce, trade and exchange make other people more valuable alive than dead, and mean that people try to anticipate what the other guy needs and wants. It engages the mechanisms of reciprocal altruism, as the evolutionary biologists call it, as opposed to raw dominance.”
“Morality is not just any old topic in psychology but close to our conception of the meaning of life. Moral goodness is what gives each of us the sense that we are worthy human beings.”
    Steven Pinker

Professor Rick T. Miller: “The Categorical Imperative Made Easy” 11:00

A. C. Grayling: “Closing the Modern Mind” 59:33

Immanuel Kant: “What Is Enlightenment?”

“a Short Summary of “What Is Enlightenment?””

Mark Twain and Robert G. Ingersoll on The Effects of the Enlightenment in Their Time


Wikipedia Articles:
the Golden Rule,
Nobility,
Immanuel Kant,
Kantian Ethics
Age of Enlightenment


Kant also explained why it is wrong to take advantage of someone:
“Everything has either a price or a dignity. Whatever has a price can be replaced by something else as its equivalent; on the other hand, whatever is above all price, and therefore admits of no equivalent, has a dignity. But that which constitutes the condition under which alone something can be an end in itself does not have mere relative worth, i.e., price, but an intrinsic worth, i.e., a dignity.”
“Act in such a way that you treat humanity, whether in your own person or in the person of another, always at the same time as an end and never simply as a means.”

“Learning to stand in somebody else's shoes, to see through their eyes, that's how peace begins. Empathy is a quality of character that can change the world.”
    Barack Obama

“The modern conservative is not even especially modern. He is engaged, on the contrary, in one of man’s oldest, best financed, most applauded, and, on the whole, least successful exercises in moral philosophy. That is the search for a superior moral justification for selfishness. It is an exercise which always involves a certain number of internal contradictions and even a few absurdities.”
    John Kenneth Galbraith