It is called ‘epiphenomenalism‘ and it is extremely baffling. However, considered from a different point of view – it’s as simple as ABC.
The behavior of the world/universe is governed by the laws of physics. Everything we know must obey the same rules, which dictate movements, electricity, chemical reactions, you name it. We may not know all the rules. Sometimes, even when we know them, there are too many factors to consider – which makes things very difficult to calculate. Yet, we tend to agree that these laws are consistent and everywhere.
Everywhere? This includes the airplanes high in our atmosphere, the tiny crystals in our rocks, and also our brain with all its billions of neurons and trillions of synapses. So if airplanes and crystals behaviors are predictable, so should be the behavior of our brain, meaning… us. So what about our “free will”?
This is, in a nutshell, the concept of “epiphenomenalism”. Quoting Wikipedia:
“Epiphenomenalism is a position on the mind–body problem which holds that physical and biochemical events within the human body (sense organs, neural impulses, and muscle contractions, for example) are causal with respect to mental events (thought, consciousness, and cognition). According to this view, mental events are completely dependent for their existence on corresponding physical and biochemical events within the human body and themselves have no causal efficacy on physical events. The appearance that mental events (such as intentions) influence physical events is merely an illusion…”
Thus, if I “decide” to move my hand, the decision and its exact timing is always a direct consequence of earlier things, not under my “control”. Reading the text above may even be one of the factors. I only have the feeling that it is my decision. In computer terms: My so-called “soul” is read-only.
Epiphenomenalism is supported by some known experiments, such as those performed by Dr. Benjamin Libet (1916-2007), who demonstrated how our brain knows of our decisions before we do. So much for the ideas of reward and punishment…