Progressonial phenomenal theory
Progressional phenomenal theory- The theory that any thing can become stronger through hard work of the mind, body, and spirit.
In the anime series when the girls finally meet Xentaus *spoiler* who is the last human on earth who claims that even though he is the last human on earth, that makes him a god. Tring to play mind games on them, it doesn't work. Xentaus goal is to make sure he is control in everyones life of the anthrosapians which he believes that they are lesser because they are not human.
Adoplha argues with him that even the weakest can become the strongest of all beings in time. An insect can take down anything as it trains to be it's best. Through this anything can be defeated, anything can win. It's just on how hard they are dedicated to themselves and how far they want to go in life.
Which is also a basis in the anime because the four girls are actually Goddess however they do not have any of their powers because their spiritual father wanted to see them grow and to pr