Watzlawick, Fish and  Weakland (1979) explain the operation of the paradoxes on the basis of two mathematical theories: “group theory” and “logical types theory

Group theory

This theory states that there are actions taking place within a group and make changes within the group. For example, a person in a dream, can run, jump, fight, etc.. Any change in one action to another will not end the dream. The events take place within the group (dream) without changing the group. Such an action is called a first step action. But if change is required on a higher level then it can occur only if an external action will be made separately from the group.

If we stay with the same example of a dream, in order to stop run, jump or fight during his dream the person’s state has to move from dream to awakening. Waking up is another state than the dream. Transition to waking is a change from second degree. Such a change defines the relationship between dreaming state and a waking state. Change from the top of a second is a modification of Change! Such change is always the nature of the lack – of continuity, or jump – and therefore logical that a change can be viewed from the top – without a second look – make sense.

Logical types theory:
The central thesis of this theory is that there is a discontinuity between a group and its members. A member of a group can be a part of a group but not the group. He can represent himself but not the group, and so the group can not represent the members. The terms used for the group are different from the terms that represent the member. When the discontinuity is not respected in human relations it leads to paradoxical communication (Watzlawick, Fisch, Weakland, 1979).  For example, “Humanity is the department that contains all the people, but humanity is not one of the people” (Watzlawick, Fisch, Weakland, 1979, p. 21).
When people are unable to reach any result, in particular, this happens because of an attempt to reach a solution by changing within the group. Watzlawick, Fisch, Weakland (1979) define this experience to find a solution as an attempt to do “more of the same

One of the ways out of this trap is by distinguishing between the two levels; one of element and second of the system, or one of the member and second of the group

In the case of the man from Crete, the liar paradox, we included the member (the man from Crete) within the group (“All Cretens”). And we mentioned before that a member  can not be the group.  So, this way the paradox was created

So, this is a confusing thinking which describes the formation of paradoxical situation whose solution is not in rational thinking, but in trying to settle the paradox itself. There is no doubt that the attempt to resolve paradoxical confusion has to be done outside the stereotypical framework of reasoning,.