Olga said:
Consciousness manifests itself through the brain. It can also be said that driving a car is a function of the on-board computer. But in fact, it can be both an independent function of the car (autopilot) and a function of the driver. Damage your computer and the car won't run. These are interrelated things.
In this analogy, the car's "autopilot" is like the human body, and the "driver" is like the soul, right? To make the analogy clearer, we can remove any "smart" functions from the car - like an onboard computer - and just consider the engine, the accelerator, the steering wheel and the other parts of the car. The driver is the thing that chooses where the car drives to, not any of the parts of the car.
Suppose that an alien being visits Earth and observes cars moving around the roads. The alien wonders what determines where the cars go and how they work. As a clumsy experiment, the alien tries removing one part at a time from different cars. When the alien removes the engine, the car doesn't go anywhere any more. When the alien removes the driver, the car can still move, but it does not turn corners or drive from place to place like the other cars that the alien has observed.
After many such experiments, the alien will conclude that the part of the car that controls where it goes, in a complicated way, can only be the driver. Thus, the alien concludes that the driver is the part of the car that is somehow making decisions. Moreover, the alien can investigate and learn that the squishy, biological decision maker part of the car controls the direction the wheels are pointing using another part of the car: the steering wheel. The alien can trace the connections between the steering wheel and the wheels. Similarly, the alien can trace a connection between the driver's foot, the accelerator pedal and the engine, and determine that pushing the pedal causes the engine to revolve faster (via a chain of several other causes).
The alien can keep going, taken the squishy biological beings apart to work out the connections. The alien can discover that the foot pushes the accelerator pedal because of electrical activity in the brain of the squishy biological being, for example.
The point is: if the alien continues this investigation, the alien will never find a soul that connects somehow to cause those electrical impulses in the biological brain. Unless the alien can find a connection and identify a soul as a separate part of the biological system (or one connected remotely, like how the driver's brain is connected remotely to the accelerator pedal via a series of nerves and then the foot) then the alien is justified in not believing that a soul exists.
When it comes to souls, we are all in the same position as the alien. Nobody has ever suggested how any soul could cause a biological brain to do anything at all. Moreover, nobody has ever identified any location for a soul. Souls have never been detected by any scientific equipment.
Why, then, should we think that souls are real?