A thing of any nature, as soon as it is distinguished from the other things, is also related to the rest of the world. The very distinction of two things is already a kind of relation binding them together. When related to different things, any particular thing manifests its different qualities (the different positions of hierarchy). Eventually, getting in touch with all kinds of things, it will reveal every possible unfolding, thus becoming related to the world as a whole.
Distinguishing what belongs to a thing from what is outside it, we observe that the internal hierarchy of the thing is complemented by the hierarchy of its environment. The inner and the outer hierarchies are mutually reflected. In particular, every individual thing is related to itself through its environment, and hence it plays the role of environment for itself and is reflected in itself. Such reflexive interaction with environment is the principal mechanism of development, the process that changes the thing itself.
So, the roots of any development are in reflexivity, the thing's relatedness to itself. Such a relation always implies other things mediating this relation. Thus, for structures, we complement distinguishing their elements and links as internal to the structure by a look from the outside to the structure as a whole. An element of the structure becomes related to itself due to its relation to the whole structure. Various feedback schemes implement reflexivity on the systemic level. On the higher level, the external systems that mediate feedback directing a portion of the main system output to its input become the parts of the main system; this is an example of a developing system. In general, reflexivity makes the very distinction between the internal and the external relative, which is an important feature of hierarchies.
Hierarchical development occurs when a number of things form a higher-level integrity, which obviously results in the reflection of this integrity in each component, and hence the growth of their inner hierarchies. That is, hierarchical development is of an active character, and things do not merely "undergo" or "experience" some evolution, they change their environment, and change themselves due to the reverse influence of their own products.
Any act of an object's interaction with the world implies a cycle of alternating phases of action and being acted upon, which can also be considered as the levels of some hierarchy. When a thing acts on some other thing, it undergoes certain changes; the inverse action partially restores the initial condition. Thus the thing keeps being reproduced in every such cycle of action/counteraction, but, in general, not exactly as it was, with some changes gradually accumulated. In the simplest case, such reproduction is reduced to conversion of hierarchy, leaving the object the same and merely changing its form, appearance, or its position in the world. This is referred to as simple reproduction; it has to do with all kinds of homeostasis and adaptation. Simple reproduction always brings systems to a stationary state, provided there is no external perturbation.
More commonly, things change in their reproduction, which is then said to be augmentative rather than simple. In the very common case of extensive reproduction, or expansion, a larger portion of the world becomes involved in the object's environment, while the character of interactions remains generally unchanged. This results in further unfolding the object's hierarchy. The world becomes deeper reflected in the thing, and the thing imprints itself on a wider portion of the world.
True development (intensive reproduction) implies a shift of the boundary between the thing and its surroundings, the change in the very notion of "the internal". This means that the object's hierarchy will change through the synthesis of its own hierarchy with the hierarchy of another thing that formerly was a part of the outer world. This "absorption" of outer things should not be confused with mere consumption. Indeed, consumed things cease to exist; they become entirely disassembled, to provide building blocks for some other structure. This is an extensive process, which is rather characteristic of mere expansion. In hierarchical development, several bodies become involved in some higher level activities, retaining much of their original functionality. One could speak about the formation of a collective body.
As the unity of the internal and the external, hierarchy can develop in two complementary ways, either "zooming in" and unfolding itself into a number of relatively separated inner hierarchies, or growing via binding several things in one. These processes of differentiation and integration can be mediated or inverted, which can produce very distant mutual influences of things in the world. Virtually, every two things become connected, so that the environment of a thing is reflected in that thing and, conversely, the thing becomes entirely represented in its environment. The whole world thus comes to the state of unity, which, however, is essentially hierarchical: it cannot be comprehended as a given entity, or a process—it is a synthesis of the both.
Like any hierarchy, development manifests itself as a number of hierarchical structures, with the levels of hierarchy representing the stages of development. However, because of convertibility, the same hierarchy can manifest itself as different hierarchical structures. This means that, since there are many ways for a thing to interact with the world, development may follow different routes, and different positions of hierarchy indicate the possible directions of its development. This distinguishes the hierarchical approach from other philosophies of development, which either assume a rigid sequence of stages, or picture development as a series of random changes. In reality, development is never random, but it may proceed through different stages in different circumstances.
Growth of hierarchies provides the basis of understanding time. A cycle of a hierarchy's reproduction is a natural time unit, associated with this particular path of development. Thus defined, time must obviously be hierarchical, since every cycle of reproduction looks differently at different levels of hierarchy. There is no fixed collection of reproduction cycles to serves as an absolute "clock". Every hierarchy can exhibit quite different hierarchical structures and hence different time scales. This hierarchical time differs from the sheer time variable representing time in physics and many other sciences. The latter is rather a structural parameter, referring to a specific hierarchical structure; in general, time is a measure of the level of development, hierarchical complexity. This conforms with intuitive idea of time, implying a definite direction from the past to the future, the existence of a finite "now" within each reflection cycle and the difference in "natural" time flow for different classes of things.
Since any development implies fusion of different hierarchies, the idea of development (and hence the idea of time) is inapplicable to whole world. There is nothing "outer" to the world as a whole, and any distinctions can only happen within the same global entity. However, since any portion of the world can reflect its entirety, each such portion can serve as a world to its inside, and a smaller creature living in such a "world" could conceive the existence of other "worlds", and eventually get in touch with them. However, the birth, existence and death of such partial "worlds" do not have to do with the universality of the world in general, which stays the same, beyond space and time, while incorporating all the possible modes of motion.