Panpsychism is the idea that everything in the Universe has some sort of awareness or mind. Pantheism relies on panpsychism and extends it, so it is vitally important to not only prove pantheism true but panpsychism too. The reality of panpsychism can be proven with a very simple logical argument.
The Argument
We know from biology that thinking humans are collections of individual living entities called cells and that these cells are composed of molecules. We know from chemistry that molecules are composed solely of atoms. We understand from physics that atoms are composed of subatomic particles which ultimately are composed only of elementary particles. Elementary particles are simply packets of energy. Energy packets are just energy enclosed within a field.
Everything that a human does can be traced down to interactions of these energy fields. Nothing we do can be caused by anything else unless you believe in the existence of magical paranormal forces. So, the only logical conclusion is that human mental states result from the interactions of energy packets or energy. The Universe, all that is, is composed only of energy and therefore is a vast sea of mentality.
Argumentum Ad Absurdum
Another way to prove the reality of panpsychism is to illustrate the utter absurdity of the opposing argument that the building blocks of matter have no awareness and that awareness simply appears from nowhere at some indeterminate point.
So, according to some anti-panpsychists, a human zygote has no mentality but mentality magically switches on at some precise point in its development. No mentality, then after one more neural connection it magically appears from nowhere.
Other anti-panpsychists will admit that cells have mentality but maintain that the atoms that compose them don’t. So at some magically precise point in evolution, one more molecule was added to to a primitive cell and then mentality magically appeared from nowhere.
The blatant absurdity at work here is that no actual mechanism is proposed for the development of awareness. Awareness simply appears out of nowhere for no reason at some indeterminate point of development.
Our explanation on the other hand has no such problem, awareness is simply ubiquitous. Awareness is a fundamental property of the most simple form of matter, energy. When organized into a sufficiently complex intercommunicating system, the sum total of energy is aware of itself as a system.