From the series: 6 Ultimate Reasons Not To Be An Atheist?
#6 Atheism cannot account for absolute truth
The rationality on the video doesn't really grasp the full implications for the problem of absolute truth. It's answer doesn't actually give an answer, it just pushes the problem back to beyond our grasp to a mind outside of time. To have rationality presupposes a rational mind, apparently.
Consider a moth. Now we can see that a moth would spiral into a candle and get consumed in the flame. Yet that mechanism has served the moth quite well in the millions of years before there were candles. A moth can navigate by light with no knowledge whatsoever. The implication being that the structure of the world is itself a limiter, and life by natural selection can build means to operate within the world.
The argument itself is somewhat bemusing in that it uses the qualifier absolute then all it does is try to argue what argued back in point four. And since that is covered, it should be that nothing needs to be explained. Though it would be a missed opportunity to talk about the nature of absolute truth.
I'm not going to make a case for absolute truth, rather I want to make a case against absolute truth. Beyond logic, mathematics and the cogito - there is no absolute truth. And on this there are two limiting factors. First is the vantage point we have in viewing the universe, the fallibility of the senses and mind. Second is the indeterminacy that seems to be built into nature itself.
It's one thing to make statements such as 2+2=4, all triangles have 3 sides, or all bachelors are unmarried. Such statements are true by definition. As argued previously, one doesn't need to see the addition of two and two bananas to know that there would be four bananas there, just as one wouldn't need to survey very bachelor to see whether they are unmarried (or any for that matter). But for statements of particulars such as all cars are red, one cannot use the same inductive logic for all it would take is one non-red car to make such a statement false.
Take a ruler, one with a straight edge. At least to us it would look straight. But how would it go on the microscopic level, or for that matter on an atomic level? On the level of magnification that visible light is still active, even the straightest structures aren't deadly straight. For our purposes here in what Richard Dawkins calls middle world, it's good enough for what we need.
In the very small, it is a world alien to us. Quantum physics it seems is beyond anyone's grasp. Yet such a system of physics has one advantage, it has demonstrated resilience. One of the triumphs of 20th century science was a theory of quantum electrodynamics where Richard Feynman puts the accuracy akin to measuring the width of North America to the width of a human hair. Yet it is not absolute.
Laplace in the 19th century made the boast that if he had all the knowledge of the current state of the world that he could predict the future to infinity. In the 20th century however it was shown that one could not do such a thing. Heisenberg's uncertainty principle prevents absolute knowledge in such a manner, that as observers there is a limit to observation. If modern physics is indeed correct, then it is impossible to expect absolute truth.
But all is not lost. It's important to remember just what you are sitting in front of now. The computer that is allowing you to see this message is a device whereby the flow of electrons through semi-conducting material allows for logic gates. An average device sitting in any given home in the western world these days is capable of mathematical power that rivals the whole human species. The success of the scientific endeavour can adequately be captured in the pervasiveness of applications of knowledge in civilisation. Skyscrapers, rockets, global satellite networks, global communications network, supercomputers, eradication of diseases, vaccinations, antibiotics, turkeys, etc. The list goes on and on.
Long story short, science works. It's endeavour is far from perfect, it has the problems associated with human observation and inference, and it's limited by our place and time in association with observation. Say tomorrow a lab through mimicking natural processes is able to get from inorganic chemicals to replicating protocells - that scientists are able to achieve abiogenesis in the lab. This wouldn't solve how life arose on this planet, we don't have the ability to see exactly what happened. Rather it gives us a model for how it could.
Science doesn't deal in TruthTM. It's a means of modelling reality, working out how reality works. Our desire for a God's eye view is something unobtainable, and a dangerous endeavour. Science is what we can know despite being fallible, the wise words of Jacob Bronowski in his wonderful series The Ascent Of Man. Even better is the wise words of Obi-Wan Kenobe "Only a Sith talks in absolutes". It seems that those who aspire to absolute knowledge are pushing themselves down a dangerous path. It leads to intolerance, a rigidity of dogmatism that any person should wish to avoid. To err is human, instead we find those trying to control others by making absolute moral proclamations unfettered by consequences or rightness.
Unlike other rebuttals, I want to finished with the aforementioned Bronowski from an episode of The Ascent Of Man called Knowledge or Certainty. Early in the episode he made the profound pronouncement "There is no absolute knowledge. And those who claim it, whether they are scientists or dogmatists, open the door to tragedy." The following video sums up the notion of absolute knowledge for me.