I would argue that it can't. Theism appears to be the default belief system of humanity. Every ancient civilization believed in God or gods. It wasn't until around 300 BC that we saw the beginnings of atheism from the Greek philosophers. Their debates about God's existence sounded remarkably similar to the debates we have today. Atheism would largley take a hiatus for over 1,500 years as Christianity became the dominant belief system of Western civilization. However, during the so-called Age of Enlightenment, atheism was given new life by men like René Descartes, Voltaire, Nietzsche, and so on.
Atheism is defined as disbelief or lack of belief in the existence of God or gods. But to have a disbelief in God, there first has to be a belief in God. The belief in God came first, and then the disbelief in God came second. If there was no belief in God to begin with, there could be no disbelief in God. Put another way, atheism was born out of theism. It came about as a response to theism, whose sole purpose was to counter the belief in God. Beyond that, it doesn't have much to offer, which is why it has never had mass appeal. The vast majority of the world's population (some 84 percent) continues to believe in some sort of deity.
But suppose hypothetically that there were no more theists left in the world—an atheist's dream come true. The end result would be that atheism would lose its foil and its reason for being. There would be nothing left for atheism to contend with. That makes atheism dependent on theism to survive. In short, I don't believe atheism could survive without theism, but theism can and has survived without atheism.
Atheism is defined as disbelief or lack of belief in the existence of God or gods. But to have a disbelief in God, there first has to be a belief in God. The belief in God came first, and then the disbelief in God came second. If there was no belief in God to begin with, there could be no disbelief in God. Put another way, atheism was born out of theism. It came about as a response to theism, whose sole purpose was to counter the belief in God. Beyond that, it doesn't have much to offer, which is why it has never had mass appeal. The vast majority of the world's population (some 84 percent) continues to believe in some sort of deity.
But suppose hypothetically that there were no more theists left in the world—an atheist's dream come true. The end result would be that atheism would lose its foil and its reason for being. There would be nothing left for atheism to contend with. That makes atheism dependent on theism to survive. In short, I don't believe atheism could survive without theism, but theism can and has survived without atheism.