Occult Casters Using Only Psychic Magic?

[Palanan]

When I first opened Occult Adventures, I was surprised to see that the casters’ spell lists draw heavily from other Pathfinder books, rather than being limited to the new psychic spells alone. For some reason I’d had the impression that Occult Adventures was a standalone book, and that psychic magic was a self-contained subsystem.

Clearly not; but now I’m wondering, would a class like the psychic or the mesmerist be able to operate effectively if they only had access to the new spells in Occult Adventures? Or do they need to draw spells from the APG, the Completes, etc. in order to hold their own?

[Florian]

It´s a good thing that it´s no self-contained subsystem but draws from the regular core spells. Keep in mind that most core spells cover the basic functions of "magic" and have the best integrated support so far, like Summon Monster and the accompanying feats.

That gives you the option to use rules and material that is already known, but play it in a "psychic flavor" of your choice.

[Dracul3S]

They need more than Occult Adventures. I think a mesmerist or spiritualist can not even work if only restricted to spells from that book. A psychic... I don't know. No one I know seems to be interested to play that class. An occultist literally can not work. They have implements that would have no spells at all.

[Milo v3]

There really is no reason for it to try and create psychic versions of spells like "Dominate Monster" or "Telekinesis", when those spells already exist. Removing the standard spells from the classes would just be broken.

[Sayt]

There really is no reason for it to try and create psychic versions of spells like "Dominate Monster" or "Telekinesis", when those spells already exist. Removing the standard spells from the classes would just be broken.
This basically hits the nail on the head.

Psychic magic fundamentally isn't a new subsystem, it's an extension of spellcasting with a few unique rules. Arcane casting has spell failure, Divine has alignment restrictions, Psychic has alternative spell components.

[Psyren]

There really is no reason for it to try and create psychic versions of spells like "Dominate Monster" or "Telekinesis", when those spells already exist. Removing the standard spells from the classes would just be broken.

Indeed, and it even goes beyond the fact that there's no reason to do this - it's actively detrimental, as psionics proved. Because psionics were separate from magic, designers had to include a separate "new psionic powers" section in every subsequent splat, when they even remembered/bothered to do that much. Meanwhile when Pathfinder designs a new spell, all they have to do is throw "Mesmerist 4" or "Psychic 7" on top, saving both development time and page real estate. The same goes for items, feats, even prestige classes - because psionics was separate, it missed out on a lot, whereas the Psychic gets free access to a lot of good stuff just by virtue of being considered a spellcaster.

[Florian]

Indeed, and it even goes beyond the fact that there's no reason to do this - it's actively detrimental, as psionics proved. Because psionics were separate from magic, designers had to include a separate "new psionic powers" section in every subsequent splat, when they even remembered/bothered to do that much. Meanwhile when Pathfinder designs a new spell, all they have to do is throw "Mesmerist 4" or "Psychic 7" on top, saving both development time and page real estate. The same goes for items, feats, even prestige classes - because psionics was separate, it missed out on a lot, whereas the Psychic gets free access to a lot of good stuff just by virtue of being considered a spellcaster.

And that in turn leads to occult classes being able to fill the role of other base or core classes without a hassle but still keep the psychic vibe.