hmmm honestly those things are two rather similar but also worlds different as the means for each come into being result in two very diverse realms. Love craft always shaped things to be more into worship of an god like one would back in the times of the Greek and Roman times. The cults are psychos but then again their only really mimicing the devotion that priests and devotee's had back in those times.

With demonic summoning though... thats more the complete submission to a power of either sin or darker intent, usually using cruel means to either appease or to win over a favor from said demon or entity.

I can understand why your brother may have confused the two as this is a common thing I see in a lot of these comparisons ^^ Though I wouldn't let his input on this ruin it for yah ^^

Well, it's not just that the beings the cults worship that are just immortal creatures. Demons we have context for and can understand to a degree. Their motives make sense. The Outer Gods and things of that sort from the mythos should not make sense. The very idea of getting a glimpse of them should make you nuts. Worshiping them makes you a mutant freak beneath their notice like the mites in your scalp building altars to your magnificence. You don't care and will destroy millions of them the next time you shower and use the shampoo.

Demons are cozy and close to human understanding the way we've built them up and named them and they have forms that we can grasp and deal with. The Outer Gods aren't anything we are supposed to be able to understand. A writhing secondary burst of information our senses were not meant to make sense of. Like the sunlight to a cave skulking man born without eyes in the middle of a desert. Something is burning him and he can't understand what the hell it is or how to escape it. He has no frame of reference or the knowledge of how to survive its influence. Arch demons intrinsically want in on our world and the negatively charged things we do laced with mounds of sin. The utterly alien creatures worshiped by the cult don't care. They get called or worshiped and sacrificed to and might touch these primitive things living in their limited dimension as a minor curiosity, but their whims are beyond us.

That's the difference and the appeal. Understanding(or the lack thereof) and the idea of scale. A demon can be one to one with a human or even less since we might have free will and a soul, but they don't have either or a corporeal body. The Outer Gods are beings outside of time that dwarf us the same way we dwarf an amoeba and they don't give a damn what we have unless we make ourselves passingly interesting.

You just made Outer Gods sound a load more terrifying.

This right here. Nailed it.

When you strip away all the window dressing, IE the bat-wings, horns, and red glowing eyes of the demons, and the tentacles, many eyes, or bizarre shapes of the Lovecraftian horror, the difference that remains is what they represent. Demons represent the weakness of mankind, our dark sides and our failings. Greed, Gluttony, Envy, Lust, Wrath, Sloth, Pride, these are all human traits and human failings. At their core demons are the worst of who and what we are, and by extension demonic cults are those who embrace our more destructive nature. The horror there is a mirror turned on the dark side of who we are, those temptations we have to give into our impulses and be led astray. It also goes hand in hand with the concept of damnation and to some extent karma. Those who consort with their darker nature pay a heavy price for it. And there's the fear of the innocent being tainted, that even when doing nothing wrong one can still be led astray, or forcibly dragged astray.

Lovecraftian horror is, on the contrary, about the fear of the unknown. That in the vast expanses of the cosmos humanity is small and insignificant. Cults in the Lovecraftian setting often don't make any sense because there's no sense to be made. Sometimes they get a demonic Faustian bargain, like in The Shadow Over Innsmouth, where they have an immediate material gain with a terrible price to be paid, but often times there seems to be no gain associated with their deal. What did the Wheatlys have to gain in The Dunnwhich Horror, or the cultists in The Call of Cthulhuh? They're messing with forces beyond their control for reasons we're never given because that's the point. When used properly the creatures of Lovecraftian mythos are unknowable. Logic, the greatest tool humans have, is powerless to understand them because their greatest transcend causality.

In simpler terms, demons are a fear of the inner, while Lovecraft is a fear of the outer. A fear of what we could be vs a fear of what is greater than we could ever be.

In other words if your story can swap demons for Cthulhuh and remain the same then either your themes are weak or the cult was a McGuffin.

Yeah that helps clear it up a bit.
I think I remember hearing that certain horror genres kinda hint at specific things people are afraid of. Like....
Zombies = Fear of groups of people/Mob mentality
Vampires = Fear of outsiders
Werewolf = Fear of our own inner nature

I guess in that sense Demons would be the fear of our darker nature and be a lot more human like. But Lovecraftian would be the fear of .... I dunno... stop me if I'm wrong, but I'm just going to say, Nature. That its something that is going to happen that can never really be stopped with no care of good or evil or care of life or death.
I think thats wrong just because I figured the fear of nature would be in Natural Disaster genres, but I cant think of the right wording.

To me, Lovecraft is more the fear of being wrong. The human race has this hubris about it that we know everything that we are the ultimate species of our planet and nothing is beyond our grasp. Lovecraft introduces the idea of creatures and realms so far beyond out comprehension that it would drive us mad at the slightest glimpse of it. A truth so profound as to rip apart our understanding of all things right down to the very core of out being, to realize that we never really knew anything at all and out place in the universe is even more profoundly insignificant then our limited understanding of reality cold ever hope to even scratch the surface of. In the Lovecraftian universe we are less then dirt to these things, and that's fucking scary in ways that is really hard to justify in words.

Typically yes, you are correct on all your points. Horror is fundamentally a very psychological genre and whether the creators realize it or not the memorable stories stick because they touch a never deeper than just jump scares. The long lasting monsters have some element that we as a species or a culture can latch on to. Now with all metaphors and symbols the meanings can change in different hands, but typically what you pointed out is correct.

While I wouldn't say 'Nature' is the best word for it, I agree with your assessment. A hallmark of Cosmic Horror is insignificance. Think of Carl Sagan's Pale Blue Dot quote. In a way that's terrifying. Or to simplify it even further, we are the Whos in Whoville and Horton doesn't care. It's the idea that the sum total of all humanity, from its greatest triumphs to its darkest atrocities, is nothing. It's worse than sitting in judgement of the almighty and being found guilty, it's finding out you're beneath being judged at all. A thing a lot of people seem to forgot is Cthulhuh, great Cthulhuh who's mere presence shatters minds and can end the world once awakened, it's the strongest entity. The thing that humanity is utterly and hopelessly powerless to stop, that can outlast death, is a punk. We're so far down the ladder we can't see the top.

And remember with insignificance comes hopelessness. You can stand against the zombie hord; you can survive, hold out, learn to move around them. Vampires you can defeat; stake to the heart, kill their leader, sunlight, garlic, holy icons, running water. Werewolves you can destroy; silver weapons or barring that sturdy doors on full moons. Even demons can be banished with faith, holy icons, and the power of the almighty. But there's no fighting cosmic horror. Best case scenario you delay the inevitable or learn that the brunt will come long after your death.

Coonix puts it well, but I'd take it a step further. It's the fear that there is no right. Think of it this way; the most fundamental human instinct is to know. Other animals see the rustling bush, decide it is something that wants to eat them, and get as far away as quickly as they can. Humans, however, want to know what is in the bush first so that they best know how to run away, or failing that how the thing in the bush is going to eat them. Cosmic horror denies that urge. With zombies you can know they will eat you and you will become one of them. Vampires you can know they will bite you and you'll either die, become their thrall, or become one of them. Werewolves you can know that they will eat you or make you a furry. Demons you can know they will taint you, make you do nasty things, then take your soul to a place for them to do nasty things. Cosmic horrors you can't.

Cosmic horror is the fear of can't even.

Hope that helps clear things up. Also I love this journal.

This got too deep.

Hah, I was guilty of that once but then I paid attention on what they're supposed to be after a few serious looks into the whole mythos. Honestly, the fact that he went with Cthulhu == Satan understanding is as wrong as comparing Hades with Lucifer. They're very different but takes a while to make that mindset go away to comprehend what the fuck is going on between the cults.

Just explain that the cults usually acknowledge that the world will soon get eaten by a giant squid from space so they're just speeding up the process because, fuck our meaningless lives. They're never asking for power or supernatural boon like how demon cults wanted them, they wanted the world to get eaten whole while worshipping them like gods, just to show their devotion to them like in the old times. The point is, Lovecraftian stories are not about some hero trying to save the world from an ancient evil from Hell, the guy is just slowing down the inevitable in expense of going completely insane. There is no "good ending" or "winning" or "saving" here. THAT is Lovecraftian Horror and demons ain't got shit on them.

What your fucking language!
But I kinda get it now. Demons want to use humans or have subordinates and can be fought. Cthulhu doesn't care what you do or who you are, and may be fought but at your own expense usually

Sorry man, where's my fucking manners?

And yeah that's basically it. You try to fight sure, but in one way or another, you'll lose horribly at the expense of your mind or worse. Death's more of a mercy at this point really.

Some cults do try to appease cosmic horrors or the like for personal gain as well but mostly ended up getting their lives ending up much worse in the long run since they're messing with an entity that can't be truly comprehended and pretty much would just mess around with them just cause. Demons would want to have you on their side instead.

Just remember insanity and fear of the unknown/unknowable plays a major part of this mythos

Spoken like a true Cultist
NOW THE TRUTH COMES OUT! REVEAL YOURSELF!

Gonna ruin another, Jekyll and Hyde is the story of a introvert who drinks alcohol and becomes a douchebag extrovert.

Got that one from https://youtu.be/VEGvJ9GP2Gk?t=236

OMG I flipping love Dagon!!

Elder gods are such an amazing concept to think about tho not to fear to me tho.
You ever play Bloodbourne cause i think that game summed up the idea of the "Elder one" Perfectly.

You should totally play Night in the Woods if you like cosmic horror. It may not
look like it at first, but the story goes a lot deeper than you would think!

Punch him

It happens sometimes but lovecraft tends to have a higher knowledge associated with them over chaos and blood and doom demon stories focus on