According to the statement Ph.D. in Health Sciences Gaydess M.A. "Perhaps there are systems that are self-sufficient and set their own purposes? For example, we, people, as if we can set goals and fulfill them. So we are an example of independent systems?
Not so simple. There is a dualism of the same concept of the purpose: the purpose as a task for some system, and the purpose as the desire (desire) of this system to fulfill this predetermined purpose:
• The purpose-task is the need for an external system in a certain specified result, which gives the task (setting or setting) for this system to produce this result
• A purpose-aspiration is (the desire) of a given system to produce a definite result of an action equal to a given (given setpoint or setting) and a different one that is external to the given system
We set purposes before ourselves, but we always set a purpose only when something is missing, when we suffer. What is suffering? Suffering is an unfulfilled desire (from ancient Jewish philosophy). Pain is a "cry of tissues about oxygen hunger". Any physiological (hunger, thirst), aesthetic and other unfulfilled desires make us suffer, and suffering makes us strive to act until the desires are satisfied. The power of suffering is always equal to the power of desire. We want to eat and suffer from hunger until we satisfy this desire. As soon as we eat, the suffering immediately passes. We love someone and suffer until we unite with the chosen one (the chosen one). Have united, suffering disappears."

The desire appears only when we have something. Desire and suffering are the engines of evolution, without them development is impossible. Desire is our goal-aspiration. When we fulfill our desire, we achieve the purpose. If we reach the purpose, we stop acting, because the purpose is achieved and the desire disappears. If we have everything that can be thought of, then we will not set any purposes for ourselves, because there is nothing to wish for, everything is there!
If I'm hungry, then I'm excited and running around in search of food. If I'm full, I'm lethargic and sleepy. If I feel warm and nowhere pressures, I've been everywhere, seen enough of different countries and kinds, I've listened to music, I can fly, pass through the walls and be present at the same time in a hundred different places, I have everything that can be invented and nothing surprises me (happiness egoist), then I have nothing to wish for, I do not want to do anything and I do not even move a finger to do anything. Why, if it makes no sense, because I have everything? Is that if the finger is scraped, but it's again the desire → suffering → action.
Therefore, even a person, for all its complexity and development, can not be absolutely independent of other systems (from the external environment). Our purpose-tasks are always put by the external environment and this awakens our desires (purpose-aspirations), which are dictated by the insufficiency of something. The external environment forces us to move, because it causes us a deficit of something, and for the movement we need energy, which we spend at the expense of our internal resources. As a result, there is a deficit of something and a lack of internal energy, the liquidation of which becomes our purpose. After saturation, the target disappears and we stop eating or looking for food until the next failure.

Сontinuing the topic author "If there is nothing to desire, there will be no purpose. Therefore, it only seems that we are free in our desires. We are free to choose our actions to achieve the purpose and are limited only by our capabilities. And we generally do not have the freedom to choose purposes, no matter how sad it sounds. Our desires are given to us from outside and we are completely dependent on them. You need something even higher, so as not to depend on your desires. This was also understood by the ancient ascetic ascetics who were moving away from the "world of this", not wanting, not provoking their desires and breaking away from them for the sake of reaching the higher worlds. But their movement was erroneous already in its basis, because it was based on the desire to reach the same higher worlds. If desire from their point of view is a "sin", then it is impossible to achieve "righteous worlds by a sinful way"!"