Who would be the atheist equivalent of Martin Luther King Jr.?

There is not one, because whoever tried, they could never rally and organise enough atheists.
Atheists are like cats, a superior life form, but impossible to be herded.

Nelson Mandela

Simone de Beauvoir.

What MLK did for African Americans, she did for women.

“Aetheism” is a misnomer in the first place. Not believing in something is not the same as having a belief system (religion) based on that not believing.

Progressive reform and religion are independent. Some of the greatest progressive reform leaders in the past were religious (e.g. MLK).
Any aetheist leader of progressive would simply not make religion part of her/his teaching.

A lot of progressive leaders in the past (e.g. singers Woodie Guthrie and early Bob Dylan) didn’t put much “God” into their work, they appealed to the common purposes of common man.

The New Atheism movement comes to mind. You could call that a large scale coalition towards progressive reform in the area of religion and atheism. Is that what you mean?
Richard Dawkins is probably the most well-known advocate of that movement, but other prominent names include Daniel Denett, Sam Harris and Christopher Hitchens.

“I’m wondering if it is possible for mankind to have it’s own moral codes & convictions without the belief in a God.”
Well, that’s a separate question, and the answer is unequivocally yes, of course we can. Many of us already live this way, myself included.
Morality and ethics aren’t all that complicated, once you get rid of a lot of nonsense¹. My own two golden rules are “don’t be a jerk” and “make people happy”. Work towards those concrete goals and you’ll be a good person no matter what you think the fundamental nature of the universe is.

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¹ I unapologetically believe it is nonsense, for example, to believe things can be inherently right or wrong, as opposed to being subjectively perceived that way; and I also consider it nonsense to believe it’s important to cleave to abstract principles even when their concrete consequences lead to a decrease in people who are happy. These are not necessarily popular points of view.

@Fyrius Well put.
And I did not mean to be dismissive about “Aetheism” I think calling it an “ism” is inaccurate and misleading to its disadvantage. If it’s a belief system, it’s one based in beliefs a lot closer to home and heart than most.
With guiding principles like “don’t be a jerk” and “make people happy” a lot of other -isms could be vastly improved.

@dabbler
Heh. :)
(I’m, aware, though – and so should my readers be – that the first one suffers from a vagueness problem and only works very informally. Making people happy is concrete enough – you can even measure happiness on a brain scan – but what does it mean to be a jerk? What behaviours does that mean you should avoid? Maybe the meaning of that rule should be that you should endeavour to find an answer to that question yourself, and then live up to it. The essence is an attitude of good faith.)

(At age 25, my own understanding of how not to be a jerk continues to shift and evolve and expand. I’ve been studying the notion of “privilege”, it can be quite the eye opener.)

It is very possible for man to have moral convictions without the belief in God. Where do you think the concept of “God’s Morals” came from?

The morals written in the holy texts certainly came from somewhere, and considering the texts contain either obviously positive, altruistic moral suggestions (Don’t steal from people and feed the widows and orphans) or obscenely negative, self-serving suggestions (raze that village of heathens and claim the virgins as rape-slaves) there’s no good reason to assume that there was a divine hand at work. People can be good and evil on their own.

Morals have nothing to do with religion. Ghandhi was one whose belief in social justice had nothing to do with religion.

Belief in God is often an abdication of moral responsibility.

Many people believe “I am religious, thus God approves of everything I do”.

Many believe “My treatment of people on Earth is unimportant, because my REAL fate is in heaven.”

The Klan is a Christian organization. The Taliban is motivated by religion.

Atheists don’t fly airliners into skyscrapers in the name of atheism.

The Golden Rule is my moral guide, and it has nothing to do with religion.

The problem with being a reformist atheist is that you end up having to spend a great deal of your time arguing with theists instead of getting a jolly good days work done. I do tend to believe, myself, that arguing with those who stick up in your path to reform is not a great waste of time, but having to repeat yourself and then put up with a seemingly unending barrage of insults and name calling can be quite tiring. It seems that the pragmatist must, then, hide in the closet, for the time being, and allow themselves to be called a ‘Liberal Christian’ because then, they can focus on the matters that mean a damn and not spend their time arguing with fools. There is only one person more pointless than the argumentative fool, and that is the man of reason who wastes their time arguing with them.

Madalyn Murray O’Hair did much to free athiests from the repression and abuse by wasps.

@Fyrius : Actually, cultural/moral relativism is quite a popular point of view in many liberal/radical circles…

@marinelife : Why do you think that Gandhi’s religious views had nothing to do with his social justice program?

Don’t get me started on Ghandi. He was as big a hypocrite as Mother Theresa.

@Seek_Kolinahr have you read anything of Nehru, then? talk about your intellectual idealist/pragmatists

The problem I have with many New Atheists like Sam Harris is that they think that morality can be derived from science. I oppose this view as strongly as I oppose the view that morality can be derived from a holy book. I have seen the argument against scientific morality neatly put as “not being able to derive ought from is.”

Where does this leave us then? It means that we have to be willing to admit that what we think is right is based on choices These choices can be based on general guidelines that most people agree on, but the problem is in the details. Quite often, due to having only finite resources, it is necessary to choose between two desirable outcomes. It becomes difficult to become a strong advocate of such a position. How can you convincingly go around saying that the plan you support may not be ideal, but is the best that you believe to be practicable?

@Seek_Kolinahr : Yeah he was, and his views were all rooted in religion. His views on women and untouchables, for instance, were strongly influenced by his religious and cultural background. Moderately liberating, but also patronizing and patriarchal.

I don’t know much of Ghandi’s philosophy. I do know that he disallowed his wife from seeking medical care, causing her to die of an easily treatable infection. However, he had no problem accepting treatment for his own malaria.

@LostInParadise There are examples in societies where choices have been based on less than pragmatic choices and idealism and strong advocates of a set of ideals that do nothing to benefit the longevity of the population, in fact, they shortened it. It really illustrates the balance, or lack thereof, of the advocates for fiction and non-fiction. I will always side, when asked on choice regarding reality, with non-fiction.

@bookish1
(Oh, I know. And I’m glad about that. I don’t know if the second example declaration of nonsensicality has much support, though, outside certain rationalist circles.)

@bookish1 He spoke at length about the role of religion in the life of man and his own religious beliefs or non-beliefs.

Maryam Namazie is a tireless campaigner for Human Rights and also an atheist. Paul Kurtz did a great deal, before his death in 2012, to empower the humanist community and support skeptics who seek proof in favor of blind belief. British author Barbara Smoker is a humanism activist and advocate for freethought. Bangladeshi physician and author, Taslima Nasrin, has worked tirelessly for feminist human rights and the rights of secular humanists. The list is long.

My vote goes to Abraham Maslow