1. The act of imagination (not its content) is a function of the brain.
2. The brain is composed of matter, and subject to the laws of physics.
a. The act of imagination is subject to the laws of physics.
The content of your imagination is immaterial. It doesn't matter that you can imagine a world that doesn't adhere to actual physical existence. It simply matters that the only way you can do so is if physical forces inside you brain align in such a way that that happens.
There is a blog here that goes more in-depth. http://theplayfulatheist.wordpress.com/2014/04/08/is-the-universe-predictable/
A small quote:
2. The brain is composed of matter, and subject to the laws of physics.
a. The act of imagination is subject to the laws of physics.
The content of your imagination is immaterial. It doesn't matter that you can imagine a world that doesn't adhere to actual physical existence. It simply matters that the only way you can do so is if physical forces inside you brain align in such a way that that happens.
There is a blog here that goes more in-depth. http://theplayfulatheist.wordpress.com/2014/04/08/is-the-universe-predictable/
A small quote:
Having free will does not mean that we are not controlled by the laws of nature and causation. It does not mean that at any given moment we can decide to do something completely against our natures. Free will is the recognition that different people, at different times, will react differently to relatively similar circumstances. This is not despite causation, it is the pinnacle of it. Every photon of light, every vibration on our eardrum, every touch against our skin, has sent a signal into our brain that has shaped it and its network of synapses, so that at every moment we may do, think, or say something that we might never have even predicted we’d do ourselves.