We refer to the existence of life after death as a belief not as a fact. The arbitrator of what constitutes a fact is science. Something is real, a fact, if science says so, clearly and unequivocally. There has long been a very clear recognition that some things that we may hold dear, even stake our very lives on, don’t pass muster as scientific facts. The existence of God is a prime example. Science recognizes that such things cannot be proved or disproved because they have to do with nonmaterial phenomena. Science is based in materialism and addresses what is referred to as the natural world. The bedrock assumption is that everything in the natural world ultimately derives from physical mechanisms and processes.
Our bodies including our brains are physical entities. It is our brains, science tells us, that produce consciousness. With no active, functioning brain, no consciousness is possible. Without consciousness nothing resembling our human ability to know ourselves, others, and the world is conceivable. If life after death exists, it must be conscious life. But without a brain to produce consciousness, from a scientific perspective such life is impossible
However, some philosophers and scientists have speculated that the brain may not actually produce consciousness. Rather it may act as a kind of reducing valve through which a vast sea of cosmic consciousness or information is filtered making it available to our human minds. One way of explaining this involves the analogy of a television set which filters and makes accessible one program out of countless others that exist in the world. True, when we turn off the TV we stop receiving the program, but programs themselves are not produced in the TV. From this perspective, when our brain dies, consciousness doesn’t necessarily simply cease.