It's been a while, but what the heck. The 40k hobbyist boards seem to be on a bit of slump at the moment and the question seemed interesting. With the caveat (as always) that this represents my own reading of the disparate background materials, though I shall try and make it clear where personal interpretation intersects with the official 'fluff.'
So, what is sorcery? It seems that one of the first places to start is what Foalchu referred to as the "anthropological lens." As most of our information comes from the perspective of the Imperium of Man (even, arguably, the information on the xenos
breeds), it is not surprising that in many ways the buck stops there. Thus, in the Imperium of Man, the term "witch," "sorcerer," "wizard" etc. seem to be bandied around regardless. Generally speaking, for them, it seems that any form of monkeying around with the warp is bad mojo
So, form the perspective of the Imperium it's really a question of who is throwing the name around as to whether you're engaged in sorcery or not.
In terms of the wargame mechanics, there isn't a whole lot of difference given the level of granularity of those mechanics--the powers of sorcerers and psykers are represented in a similar fashion.
What about the roleplaying game, Dark Heresy
(or Rogue Trader
for that matter)? Well, there it shares the same level of confusion. Sorcery is just represented as a type of psyker power that you need "Sorcery" Talent for. It doesn't really address the question nor is it, IMO anyway, particularly flavoursome. Quite the opposite in fact.
On the other hand, there are bits in earlier bits of the book (Malleus
section of Disciples of the Dark Gods
that allude to some form of connection between sorcery and ritualism
, or at least Chaos rituals. More on that latter.
It has been suggested that sorcery is directly related to dealing with the powers of Chaos (or perhaps other warp entities). Dark Heresy
would counter that suggestion, since it defines--not very well, but it does--between two "paths" of sorcery: the left-hand
path, which deals more with summoning and binding of spirits, and the right-hand
path which deals more with apotropaism (hexagrammic wards, producing swords that work against daemons, etc.).
Personally? My interpretation is still being formed, since it is partially formed around RPG rules in an alternate system. On my own benefit, the primary difference between a psyker
and a sorcerer
relates to the premise of ritualism. A sorcerer, by default, works through the proxy of rituals regardless of whether they are themselves a psyker. Through the use of rituals they are able to do things that otherwise they might not be able to do, e.g.
work at a distance, generate more power then they alone could do, etc.
While some have the "talent" for being a sorcerer, there is nothing stopping Jo(ann) Q Imperium from picking up a malefic codex (or other book) and using it to whatever intent is codified therein. (Well, other than the Inquisition.) They are now a dabbler, darned their heretical eyes.
Of course, different people have different abilities, so I'm sure that there are those individuals that are more "gifted" at Sorcery than others. These are the true Sorcerers, not just dabblers, and they come in different ranks, e.g.
Adept, Master etc. (See Disciples of the Dark Gods
where it uses "Master Sorcerer," though again seems to miss out on any flavour.) I would imagine that higher "ranking" Sorcerers might be able to replicate similar effects to psykers, e.g.
taking less time, not requiring all the symbolic materials and associations, or not requiring that it be done in a specific locale or under propitious astrological (or whatever) situations.
Erm, I'm rambling. Anyway, in answer to the original poster:
Could someone be a powerful psycher and powerful sorcerer?
Yes. In Dark Heresy being a sorcerer adds to your Psi attribute, which makes you a more powerful psyker. It doesn't quite explain this, but there is precedent in the setting at least.
Does sorcery have to do exclusively with the more demonic side of things, or are they merely different names for the same thing.
No, hence the two "paths" of magic: left and right.
If so, why were the sorcerous thousand sons disliked, given that the emperor himself is a psycher...
Because the Emperor didn't like Sorcery, because he defines it as bad. Except the good kind, but we don't talk about that.
I'm pretty sure the sourcery thing refers to forming daemonic pacts to give a psyker additional strength. I could be wrong though.
I would imagine that it might definitely be a component. Indeed, the summoning of a "daemonic familiar" is specifically mentioned in the Radical's Handbook
(another Dark Heresy
40k RPG supplement). One imagines that many malefic codices deal specifically with how to get in touch with daemons.
Certainly, though, I would imagine that a pact with a daemon would give one access to all kinds of abilities, perhaps even those that replicate that of psykers without actually having to go through all the rigmarole of becoming a "Master Sorcerer." Of course, there are things to be said by taking the slow and sure path rather than the quick route to power. It might even be proverb.
That's the way I see it. Sorcery involves bargining the power of another (Chaos God, daemon etc) for your own use.
Wards, hexagrammic/pentagrammic/octagrammic (or whatever they're calling them now) are all related to sorcery. Whether this involves a subconscious bargain with an entity is up for grabs in individual interpretations, I guess.
Erm, I'm going to stop there. Feels a bit weird to post something here. Kage