In the description of rite of pure thought it states that the GM should replace any mental disorders that does no longer apply with new ones of equal severity.

But what too do with the curses?

The point of the "rite" is that the TM no longer have any feelings or emotions and all curses are based in in emotions, pride, anger, paranoia and more. The only thing i can think of is that the TM's logic get flawed.

Your thoughts?

What is "logical" depends on your goals and prior assumptions. I could see a Black Templar techmarine with the rite of pure thought thinking it perfectly logical to exterminate the witch. They are a priority threat and must be eliminated in a cold, rational manner.

Decessor said:

Um, actually anything can claim to be logical. The only real logic is that which can survive under the scrutiny of cross examination. If a techmarine has replaced a portion of his brain with a logic engine then he simply makes those choices that survive his examination without contradiction. That does not mean that his conclusions would be correct because he may not have the right information to base his conclusions upon. I would however suggest that pre conceived notions that are represented through traits such as hatreds would not survive the conversion to a logic driven mentality. As for things like the red thirst, its hard to say whether or not the cybernetic replacement would remove the source of the hormone imbalance that causes that state.... or even if that is caused by anything other than some "magical" psychic backlash.

Who said anything about logic being always correct? Some pretty ridiculous things "proven" with logic historically. In any case, if you start with the axiom "pyskers are inherently untrustworthy and should be shot on sight" then you're not going to find much evidence to prove that line of thought "incorrect" in the 40k universe.

As for hatred, It is perfectly possible to despise and hate an entity without passion. "Priority target. Eliminate."

The red thirst is a tricky one though. It depends as you say on what the GM decides actually causes the red thirst.

Decessor said:

I'm fairly certain that I did not say that logic is always correct. When someone uses logic to determine something the out come is clearly going to be greatly affected by the foundations of that individuals world view. Logic is a set of tools, thats all....

As for the hatred without passion, well here's the definition of the word.

Hatred (or hate) is an intense feeling of dislike. It may occur in a wide variety of contexts, from hatred of inanimate objects or animals, to hatred of other people, entire groups of people, people in general, existence, or everything; themselves (misanthropy; self-loathing).

So as you can clearly see in the above definition, you cannot hate without feeling. The knowledge that something is your enemy and must be destroyed for your survival has nothing to do with the emotion HATE .

A little review of what logic is may be called for.

Logic is used to examine arguments - to determine if they are valid and fallacious.

N.B. The term 'argument' is this context is not the typical Jerry Springer usage. A logical argument is constructed of premises and conclusions. Probably that most common form of this sort of argument is a mathimatical one like 1+1=2.

Logical analysis can be used to determine if the conclusions flow from the premises in a valid way.

i.e.

Premise 1: All roleplayers are geeks

Premise 2: Fred is a roleplayer

Conclusion: Fred is a geek

or

Premise 1: The conclusions of logically valid arguments are always true

Premise 2: It has been logically concluded that you are smelly

Conclusion: You are smelly

Both these arguments are valid. If the premises are true the conclusions must be true. However, some (or all) the premises may be false, and still the conclusions may be true. The critical principle is 'rubbish in, rubbish out'. What logic protect you from is 'truth in, rubbish out'.

The definition of hatred certainly precludes emotion. But in game terms, a "logical" strong preference or experience at slaying a particular type of foe could be handled with the same talent. Fluff is easily changed after all.

Chronomaniac Timewarper said:

Think of the movie I Robot; the computer that controlled the robots came to the logical conclusion that all humans are a threat to themselves, and therefore must be kept safe from each other and themselves... even if by forceful restraint.

This evolved from the notion that no harm can come to a human being.

See how a Primarch's Curse could still work?