Our mind allows us to conclude that many completely heterogeneous objects of the surrounding world can be classified according to certain criteria, isolate some objects and combine them into a group. For example, when we see several similar cats, we say: "This is a Siamese breed of cat." The variety of cat breeds is the biological species of the animal, known as the "domestic cat". The similarities of cats, Pallas, leopards and lions will allow us to combine these animals into “cats”, and cats, rodents and primates into mammals. As we see, even the most superficial knowledge of the world reveals certain structural levels of the organization of matter.
The word "structure" in translation from Latin means an ordered structure, location. It can be assumed that in the structural organization elementary parts form the totality. But not everything is so simple: a brick house consists of bricks (in this sense, a brick is an element, and a building is a system), however, neither a stack of bricks nor a senseless pile of bricks are not a house. In order for the parts to create integrity, the levels of organization of matter must be subordinated to a certain hierarchy and there must be interaction between them. If a brick breaks away from the house, it will not cease to be a house from this - therefore, the element plays a subordinate role with respect to the system.
Therefore, we can assume that the structural levels of matter have basic principles. Integrity is a fundamental principle: the sum of the properties of elements (for example, bricks) is not identical to the property of a house as a home. The structural nature of a certain order ensures its stability: bricks are fastened with mortar, support the roof. The system has a clear hierarchy and subordination: each object can be considered as an element and as a whole (for example, in relation to a brick a house is a structure, and in relation to a housing estate - an element; also a brick is a system in relation to its constituent material particles).
This begs the question: how many are these structural levels of the organization of matter? Epicurus wrote that all matter consists only of atoms and void. Now science has moved a little forward, and with the help of technology we can say that matter consists of molecules that are the collective order for atoms, those are a system for electrons and nuclei, nuclei for nucleons, and nucleons for quarks. Modern science has stopped at quarks, but theoretically this is not the limit. It is possible that in a couple of decades, scientists will reveal even smaller particles of matter.
This is if you look deep into. And if you look in breadth - which system is the largest, considering as elements all the structural levels of the organization of matter? Our planet Earth, with its animate and inanimate nature, together with other planets and their satellites is included in the solar system. The sun is not the brightest star lost on the edge of our galaxy. And our galaxy is in some kind of stable interaction with other galaxies, forming a metagalaxy with them (the visible part of the Universe). Is there some kind of Superworld about the theoretical existence of which Giordano Bruno spoke in his doctrine of the plurality of worlds?
And finally, a few words about the connections between the elements that permeate all structural levels of the organization of matter. A hierarchy relationship (in other words, a “vertical”) is not the only one. In wildlife, there is very often a horizontal connection, where the constituent elements are not subordinate to one another, but interact, supporting the system. So, in the human body, the internal organs are not inferior to each other in importance and are not subject to each other. In inanimate nature, heterogeneous elements, making up the system, can change their properties and acquire new ones. Here is a simple example: H2O is a water molecule. Hydrogen burns, oxygen supports the combustion process. However, when combined, they form a substance that extinguishes the fire. Thus, the system has some new properties that are inherent only to it as a kind of aggregate.
