Master collects the info through his first function . This means that he/she has an estra ability to feel the beauty and harmony and is very sensitive. He is aware of how comfortable he feels, is dressed, smell and other sensations and this is sort of info is selected from the world as a main interest. The person might go for different new expereinces like trevelling, tasting new food and etc..
Creative function is that means that he uses the info about sensations and applies it very practically for himself and for others. For example, he will not do the work if it will not bring a practical result - does not waste his time on "nonsense". If he does not like somebody he will try to avoid the person. If he feels that the task is too complex he will drop it. He is creative in a very practical sense -e.g. can make new things out of old ones.
Master will probably feel upset if somebody start to criticise his work as useless, not buaetiful or not comfortable. Or may if somebody can not simply appreciate his effort and practical knowledge.
Now I attempt not only to give the description of the third and the fourth functions of ISTP but also to describe how the functions influence each other. I might be wrong or not complete. I am open to any kind of critique as I hope it will help to our better understanding of the type.
According to socionics the weakest function of ISTP is extraverted emotion
Filatova writes that ISTP appears to be stable and unemotional because he prefers to hide his feelings. However, he can unexpectedly for the others exploid, if somebody will offend him and especially in public. He worries that people will laugh at his feelings, that is why he hides them. He is a sensitive person at the same time and will feel upset if the loved ones do not show enough attention.
ISTP fourth functions is extraverted sensorics . Jacubovskaja writes that ISTP is brave and does not fear anything. However, he tries to be emotionally stable and not to upset others with his emotions.
Socionics do not explain how they come to certain conclusions. So we shall try to interpret it the way we want and think to be sensible.
Look what Ganin said about hidden agenda:
by Sergei Ganin
Every person has a hidden agenda. This agenda often governs one's intentions and behaviour. People are often unaware of its origin, but can always feel its significance. Some people are more affected by it than other people. Every type requires an optimal condition in which it can function properly. If such condition does not exist, a person will normally attempt to create it. However, due to the nature of the hidden agenda, if and when the optimal condition is reached, the person will occasionally put themselves in a situation where the stability of this condition is threatened.
There are eight such agendas/optimal conditions:
ENTp, ESTp => to be loved
INTj, INFj => to be healthy
ESFj, ESTj => to be perfect
ISFp, INFp => to understand
ENFj, ENTj => to be wealthy
ISTj, ISFj => to believe
ESFp, ENFp => to know
INTp, ISTp => to love
According to Ganin, ISTP’s the hidden agenda is to love. I see it is associated not with the six function but directly with the third and weakest function. Ganin actually saying that Love or positive emotion is that happy condition for ISTP. Ok, the six function in socionics states that this function is associated with the person’s level of activity. It either energises him or deactivates him. Love or positive emotion does the job for ISTP - keeps him happy. However, according to socionics it is actually introverted emotions - something which he feels inside. Which is understandable if we consider that his first/dominant function is introverted sensing - to feel good is very important for ISTP anyway. So we can say, ISTP has got a drive to love, to feel good and so it is his hidden agenda.
But his third/weak function is extraverted emotion.
Third function is the area of potential danger: ISTP does not orientate well in the world of people’s emotions. That is why, his motto is according to socionics: :‘Do not express your feelings openly!’ He is afraid of powerful (negative/positive?) emotions. Why? May be because he is not clever enough in expressing his emotions…may be he feels lost sometimes not knowing what exactly he supposed to feel and to say? May be he feels some sort of deficit in his ability to love or express love? This is not only his problem - INTPs are in the same boat. Weak extraverted emotion makes him sensitive as he does not feel strong enough in feelings and that is why his hidden agenda according to Ganin is to love and probably to be attached to another person.
I believe, that under the normal living conditions ISTP fears the negative emotions coming from the outside . Under stressful condition, he can develop some sort of paranoia that he is uncapable of expressing positive emotions or being able to love, to be attached to somebody problems in the relationship because of him! -then he will think he is loosing the plot.
What I am saiyng is that we can look at the functions by separating them in 1,2,3,4,5,6, 7, 8 or we can simply take any of the fourth functions and play with it -look what do they mean. For example, if you are strong in introverted sensing (your first function) , it does not mean that you are uncapable of extraverted sensing - Rubbish! You are strong in it as well, you just don’t use it because it costs you extra breath. That is why Jacubovskaja says about Gaben/ISTP - he is very brave. Extraverted sensing is a dominant function of ESFP/Napoleon. That means Gaben at times may show character of Napoleon if he wants to.
Now the last but not the least, ISTP’s fourth function - introverted intuition . According to socionics this function is directed into the future -predicting, feeling the time, the six sense, poetic/mystic inspiration. I say, that is the fourth function is the function of ambition and not as weak as we used to think. In socionics the fourth function is weak but the 8 function (which is only differ from the first in the extraversion/introversion -out/in direction) is strong, he just need to work hard for it.. Do we actually need to do this separation? I don’t think so!. Socionincs would suggest that ISTP are strong in extraverted intuition - which is ability to analyse, to see inner structure of the object/person. I would say that ISTP’s ambition and strength is in both: in and out direction. But I do agree that you have to pay for it as it is not something given to you for nothing. on the other hand if we consider what is his first function we can assume that the first function will limit the abilities of the fourth function to the area fo it's interest: direction from the first to the fourth function.
How the third and fourth functions interact? Easy: If you work hard on the fourth function - it makes your weak third function stronger - gives you protection, a sense of security within yourself. How can we apply this model to ISTP? If he will get enough knowledge or develops his intuition to a higher degree and - he will see inside of not only objects but also people. He will be able to analyse them, to predict their behaviour and the expression of their emotions - he is going to protect himself better from hostile emotions of the outside world. This is the direction from the fourth function upon the third function upon the first .
If we shall consider the influence of the fourth function upon the first: we can say, he will feel good by not wasting his time on doing damn routine things and instead he will do something perfect and original, something which will make him to feel real good about himself,to be the best -to be ahead of what is known or achieved. He is the MASTER at the end of the day.
According to socionics, Gaben/ISTP is a lazy person and does not like to do routine things but prefer to be engaged in something more special. Why? May be because his first function is to create the harmony within yourself (in) but not as such in outside world. So he will do things which will make him feel good and not everything what needed to be done.
At the end I would like to add, while using the concept of the 8 functions we can take more flexible approach in the directions of influence between the functions.