I recently came across an article entitled "Synthetic biology: 'playing God' is vital if we are to create a better future for all".  

As you can imagine, the article itself is primarily focused on the advance of science and the counter-arguments that are often viewed as being "anti-science".  Many of the comments support this view by arguing that we have been "playing God" since we domesticated the first animal, or planted the first food plant (1).

One of the primary issues is what this phrase of "playing God", actually means and the article addresses that point (2).

"Detractors use the phrase "playing God" to provoke emotive opposition without defining what it is about synthetic biology that is qualitatively different to the previous advances that they enjoy and benefit from every day. Should we go back to the time before humans started playing God through their development of sanitation, vaccines and measures to counter widespread child mortality?" (3)

"If playing God involves developing technologies that cure diseases, clean up pollution and create new forms of fuel, then these potential benefits need to be considered without the burden of vague, simplistic soundbites."
http://www.guardian.co.uk/commentisfree/2012/jul/27/synthetic-biology-playing-god-vital-future

So, the general perspective here is that "playing God" is necessary for our future, and that we may actually have a moral obligation to pursue it.  

In my view, we need to stop "playing God" and face the real issues of what it means to "be God".  Let's stop dancing around the subject here, because "playing" obviously implies that we aren't particularly competent to be God, so, like children, we are merely playing at it. To stop playing we need to identify what this concept of "God" actually involves, because we seem to be focusing solely on accomplishments, and despite how scientifically or technologically marvelous they may be, they aren't necessarily relevant when it comes to the concept of being a "God".

What kinds of things does "God" engage in?  One obvious answer is in distinguishing between "right" and "wrong", or more specifically;  justice.  It would be easy to dismiss this as being too philosophical or the domain of religion, but that's precisely the point.  With advances in technology that provide "God-like" qualities, then each usage, each application of such technology involves addressing questions of "right" and "wrong".  Ethical considerations are no longer simply a matter of convenience or abstraction.

As a thought experiment, consider our ability to cure disease.  If we lack that ability, then everything is in the "hands of God" or nature, because we are unable to affect the outcome in any material way.  Therefore we are not responsible for the outcome.  Suppose now that we can unequivocally cure this disease, but it is a quite expensive process in terms of resources and skills.  Do we have a criteria for determining if an individual can receive such treatment?  We now have to face making the decision about who should live and who should die; who benefits, who is denied.  In short, our ability to cure the disease is dwarfed by our responsibility in deciding how that ability should be used. We can certainly employ idealistic arguments about how such advances will benefit all of humanity, but we can already see our failures in delivering something as simple as food.  

Previously we could acknowledge that we were powerless to affect the outcome, but when we can control the outcome, then we have a responsibility to make those types of decisions. That is what it means to "play God" and why many people are concerned about how those choices will be made in the future.    

One of the overriding themes in many views of God is that ultimately God is "just".  This is the one trait that humans can count on, in that justice will ultimately be served.  Ironically among humans we believe that "power corrupts" and "absolute power corrupts absolutely", and yet such a condition is not applied to God.  Yet there is no reason to believe that with increased knowledge or technical abilities, human ethics will mature accordingly.  

Another concept of God has always been based on the idea that no matter what happens, every individual would be judged and "rewarded" based on their true value, the kind of people they were in life and not based on money, political connections, popularity, appearance, or the myriad number of other criteria that humans use.  So, before we get too confident in our ability to emulate God, by invoking some pre-technological era and claim how we are now countering "widespread child mortality", let's be honest with ourselves and recognize that the majority of human deaths on this planet are already preventable and fully within human hands to stop.  So, instead of arguing about some future where we can "play God".  Why not begin with what we can do now?  We already know how to stop starvation.  We already know what it takes to be non-violent.  We already know about the causes of wars.  We already know about sanitation and clean water.  

So, if we can't actually achieve all of these things when we already have the knowledge, are we also still waiting for some "miracle"?  Where is the science?  Where is the technology that will solve those problems?  If we can't deploy the "solutions" we've developed then we truly are just playing at being Gods and perhaps we aren't nearly as ready for the future as we imagine.

In the end, while we can blithely talk about how much humans have achieved and make the appropriate noises about "playing God", when it is all said and done, perhaps we should be a bit more humble and recognize that our success isn't simply a matter of how clever we are, but rather how ethical and humane.  It is then that we may be in a position to truly talk about "being Gods" instead of merely being chimpanzees with unrestrained power.

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(1) Of course, by that argument, then we could also claim that beavers are "playing God" when they construct dams, as well as any animal that modifies its environment.  In general, it's a silly comparison.

(2) Note that the purpose of this discussion is not to engage in a religious discussion of God, but rather to explore what we mean by the concept when it is employed in this manner.  As a result, none of the comments here are intended to define or constrain possible interpretations of what individuals may believe within their own religious contexts.

(3)  It is almost humorous how humans love to take credit for things like sanitation, despite the fact that every other living creature on this planet seems to have no particular difficulty in understanding it.  However, it does point to one particular aspect of science and technology that is also frequently ignored, which is that many of the "problems" we are attempting to solve are completely of our own making.  In other words, they aren't intrinsic problems of survival, but rather problems that have surfaced as a result of our particular way of wanting to do things.