No, it is a perfectly rational response made by someone who has looked at all the available evidence for a God (the kind suggested by most religions) and concluded, because such evidence does not exist, therefor the God does not exist.Is Atheism science?
If not, is Atheism just a conjecture, please?
Regards
This would be precisely the same thing as looking for the evidence that a 7,000 foot-tall, 23 legged megalo-insect existed on planet Earth, and finding zero evidence for such a thing, concluding it doesn't exist and then just getting on with your life without worrying about it any more.