Cosmicism is the belief that humanity is just a natural occurrence within the Galaxy and nothing particularly special. It focuses on logic and atheism above all and the respect for the unpredictability of nature. It is Existentialism taken to the extreme as all that humanity's destiny is chosen for them and every individual's life happens the way it does by the uncontrollably tides of fate.
You are born, live, and die. Your fate is sealed and you must accept how it must be for you live upon a grain of sand within the ever expanding Galaxy.
Cosmicism is heavily against 
progressive and 
democratic ideals as it believes that such ideals bend what a society and what humanity naturally should be. Such beliefs force different cultures to become one or bringing into The Western World a people or society that is backwater and would disrupt the natural balance of The West. Forcing these societies to conform to one another goes against their natural positions within humanity and the grand scheme of the galaxy.
Cosmicism is heavily focused on the belief of there being other beings within the universe as the creation of humans had to have repeated on other inhabitable worlds. These beings would see humanity as a fledgling civilization and species that is isolated upon their small spec of a planet. Humanity would be neither superior of inferior to these beings. Just another animal within the wilderness of the Galaxy.
History
The history of Cosmicism is also the history of the man known as H.P Lovecraft for the whole belief is forged around his views of the world and his life experiences.
Further Information
Wikipedia
Youtube
Literature
- Many of Lovecraft's writings and short-stories have some of Lovecraft's Cosmicism beliefs quietly inserted into them. Such examples of this are 'The Shadow Over Innsmouth', 'The Dunwich Horror', and 'The Call of Cthulhu'.