Allan Kardec. The book of spirits (№ 396802)

Question: Spirits having influence on natural phenomena, whether consciously, by choice or by instinctive and thoughtless impulse?
Response: Some Yes, others no. Let's do a comparison: imagine a myriad of animals, to make little by little from the sea, entire Islands and archipelagos. Do you think that this is not the purpose of his Dispensation, and that this transformation of the earth's surface is not necessary for the overall harmony? Make it animals standing on the last stages of living beings, satisfying their needs and not knowing at all that serve as instruments of God. Similarly, the lower spirits are useful in the universe; while they just start life, before aware of their actions and their will, they are already on some of the phenomena are unconscious and their engines; at first they are only performers; later on, when their minds develop, they will command and control the phenomena of the moral world. So, everything in nature is beneficial to all associated with each other.