I find it extremely interesting that many naturalists promote King's idea of human equality. But is that promotion compatible with naturalism? Human equality is a Judeo-Christian concept that is foreign to any worldview that must rely upon naturalistic evolution to explain the existence of the human race. Here's what I mean:
Survival of the Fittest
One of the major pillars of naturalistic, evolution is "survival of the fittest". This simply means that the lifeforms most fit for a certain environment will propagate their offspring into the next generation; lifeforms that possess any feature that inhibits their survival, will eventually die off. Value is assigned based on this survivability.
Notice the superlative language of the pillar- "fittest". In order for a superlative to exist, there must exist another that it is superlative when compared to. If humans are the result of "survival of the fittest" and we are not the end of evolution (mutations are still taking place today, so I guess we're not), then some members of our species are superlative to others. The genes of the superlative humans will survive into the future.
Human Equality?
So what? The implication is that not all humans are equal. Equality is a concept antagonistic to the naturalistic, evolutionary paradigm. Then how does the concept of "equality" exist? It was generated and propagated by the weaker members of the human species in an effort to undermine the superlative members. "Human equality" is the deception of members of our species that should otherwise be eliminated.
Of course, that is only one way to look at the situation. Those who are propagating the idea of equality may, themselves, be the ones most fit to survive. Physical fitness is not the only factor in determining if a species survives- the ability to use the brain to utilize resources in the absence of strength or agility also improve fitness. But even if we take that position, then we are still saying that one set is superlative to another. The implication would be that those who do not promote equality should be eliminated.
"Survival of the Fittest" vs. "Human Equality"
Notice that regardless of the position that is taken, that I must use the value-rich term "should". If value is based upon survivability, and the survivability of the set that does not promote equality is inferior to the set that does, then it follows that those who promote "human equality" and hold to a naturalistic worldview, are standing in the way of nature and devaluing the truly valuable human beings by assigning the same value to where it does not belong. Nature will prove the equation of value between the two different sets to be incorrect. If the set that holds to "human equality" is, in fact, more fit, then it will survive, while the set that denies it, will die off. The naturalist who holds to human equality would then have a protruding contradiction in their worldview (regardless of which set actually does survive)- it cannot explain the fact that one set survived in nature. Which means that either naturalism or human equality is false. Both cannot be true.
...and Christianity?
"Human equality" is only possible if the source of the value of humans is independent of the humans. The Christian worldview assigns the same intrinsic value to all human beings. It is not based on survivability of the humans (or any other characteristic of the humans), but on the fact that they are created in the image of the Being who's value is the highest in virtue of His nature. The fact that humans possess the Imago Dei (Image of God)is what assigns to all humans intrinsic value, and by virtue of the fact that we all possess it, we all have equal value.
The fact that we do survive is a product of the Imago Dei. We possess a mind that is capable of simple and complex thought- both of which can be and are used for survival (as hint to above). Unfortunately, man is fallen. One of the results of this fallen nature is the fact that man is self-focused (prideful and narcissistic). This causes man to focus acutely on his survival (survival is not wrong in itself, but the desire for it causes many to make choices based on a certain level of paranoia). Man will use this mind to come up with "ways of survival" that violate the intrinsic, equal value of other human beings (typically the illogical conclusion is one that violates another human life. They "reason" that it is the only option when it really is not). Murder is an example. In Christianity, murder is a sin because it is a direct violation of God's nature.
Changing the Course of Evolution: For OUR Survival
Let's also take the entire medical enterprise. Why do we spend so much resources (time, money, and energy) to find cures for ailments? If a member of the species gets sick, they apparently have a feature that makes them susceptible to a particular microbe or virus (or anything else), which means that they are not the fittest human (or even organism) for the environment they are living in. Why not allow nature to eliminate the weaker gene pools in favor of stronger ones? We can't really say that survival is the objective value that we appeal to when searching for cures, because of the fact that we have assigned greater value to this generation and species than to the later generations and other species (the value is relative to our species and our generation). Not only have we denied the later generations a more resistant set of genes, but our efforts are causing bacteria to mutate to become immune to our treatments. We have, in essence, worked against the health of future generations on two different levels, and even ensured the survival of another species that are not "really" more "fit" for the environment (they are dependent on unfit humans to survive). When the unfit humans die off, so do the organisms dependent on them.
This all stems from our idea that human beings who are currently alive have intrinsic value, and that value is greater than that of other life forms. Naturalistic evolution cannot explain how such value exists on an objective level; however, it can explain it on a relative level. But if it can only explain human "value" on a relative level, then it is equally acceptable to allow a person to suffer and die versus treating them to the point of recovery- whether we allow a person to die or treat them must then be determined by other people who may use whatever relative value system they wish to use (keep in mind that they cannot say that any conclusion they come up with is objectively what "should" be done, because no system they use will be objective in nature). An example would be the conclusion that someone does not possess enough resources to enhance the lifestyles or survivability of the current generation, so it is okay to allow them to die- they are not worth the resources that would be spent on treating them...in fact, this could be taken to the further point of "well, they are taking up resources from those of us who would like to survive and have the capability to, so let's end the life of the person and call it a 'mercy killing' to trick our consciences into believing that our survival was worth the ending of a life." This decision will eventually come back to what I described as "murder" above.
Fallacious Appeals to Emotion
There is something that I want to point out about the appeal I have just made. Notice that it is completely emotional. As much as I would like to call the death of the individual "murder" and would like to appeal to the emotion tied to such a term, I would not be able to. Since naturalism does not have objective moral values, a naturalist cannot call any of these deaths "murder". "Murder" has an objectively moral quality to it that naturalistic moral theories do not have room for. My appeal to the "heart strings" of a naturalist to recognize a specific death as "murder" will not work. Why? Because morality is relative. The person making the decision may use any justification they wish, and it is considered "right"; the death cannot be classified as morally wrong (murder) because it is "right" by the person making the decision. Can we meaningfully say that what is portrayed in the cartoon I've chosen to accompany this post is objectively wrong? What about the assassination of Reverend King?
Psychological Tricks
Unfortunately for the naturalist, I am not completely cut off from reason by this fallacious appeal. If my conclusion is actually false (that a particular death is objectively, morally wrong), they must be able to explain why they and/or others strongly understand that such a death is morally wrong. The emotion is real. It is present, thus its evidence must be explained. Naturalism has plenty of options. The "feeling" could be ignored. It could be suppressed. It could be denied, altogether. But how many psychological defense mechanisms are we willing to utilize to convince ourselves of the truth of our morality, ensure our own individual "value" supersedes another, and justify our belief that naturalism is true? Are we willing to accept the idea that evolution has given us a strong intuition that something is true about reality, when in reality it is actually false? If so, we must question the reliability of other evolved faculties we use to determine truth- including the mind we use to logically come to this conclusion.
Conclusion
No person in their right mind would acknowledge that a person's value is reduced to being relative to their own or that one person is more valuable than another (equality does not exist). If one denies the objective value of one person, they must deny it for all people including himself. Human, intrinsic and equal, value is one of those things that man knows to be objectively true, but cannot ground the existence of it or his certainty of it unless he acknowledges the Imago Dei. Which means that man must acknowledge that the Judeo-Christian God exists if he wishes to hold that man possess intrinsic value and "all men are created equal."
Reverend Martin Luther King Jr. based his fight for the civil rights on his worldview of Christianity. His fight does not make sense within the naturalistic worldview. Consequently, even naturalists in America owe a debt of gratitude to Christianity for the benefits of civil rights.
Check out this post by Stephen McAndrew at Songs of a Semi-Free Man specifically addressing our desire to fight for human equality.
Arthur Khachatryan at Cold and Lonely Truth has posted a comparison of Reverend King with Adolph Hitler.