Nature is the chaotic replication system that re-establishes itself when the simplifications of a garden are abandoned. The row of gourmet peas is smothered by grass and broad-leaf seed-heads which offer food for finches. Lichens transform the glasshouse pane exteriors into pastures for invertebrates. Rats set up house in the potting shed and reprocess anything digestible into droppings for the excited coprophiliacs. Considering only the primary etymological origins of the word, 'nature' is characterised by reproduction and 'birth'... cells, seeds, eggs, embryo, etc... and the consumption of a fraction of each as an energy source to sustain the process.

In general, the vast unbounded potential for complexification in the cosmos will result in a 'nature' when entities evolve to create and reprocess energy-storage substances. Once amino acid type entities reconfigure as proteins for example, and entities such as chlorophyll acquire a capacity to capture energy and store it chemically, then others obtain a benefit from the availability by developing such reprocessing strategies as scavenging, parasitism and predation. All of the energy-storage entities in the reprocessing chain, each of which is reprocessed by entities that have evolved to exploit the resource, are generally referred to as 'food'. A nature therefore, is the physical establishment and evolution of a system of food production and reprocessing. With mutual associations of convenience enhancing the potential, and replications accelerating the process, a nature of evolving food entities continues to complexify because of the intrinsic imperatives inherent in the food reprocessing and replication system. Transient entities are trialled in an unpredictable environment and evolve by developing strategies to compensate for being exploited as a food source for others.

In evolving, a nature interacts with its environment and thus becomes dependent upon it. A sudden and significant change in the environment could be catastrophic for the nature. A supernova would probably extinguish any life on a nearby planet for example. Within terrestrial nature, individuals are born with certain genetic determiners but depend substantially on their environment in order to realize their potential. As well as the vicissitudes of the earth, oceans and the climate of the physical environment, all biological entities have the factors of nutrition and predation to overcome, and in the case of humans, the influence of culture, religion, education and medicine all complicate the situation. Environmental factors are significant and determining.

What has been called 'intelligence' is the capacity to evolve increasingly sophisticated methods of avoiding being eaten, obtaining food, and successfully reproducing. Because 'success' is measured directly by 'survival', any modification that enhances the chances of an entity being able to reproduce will thereby contribute to the continuity of its species. The fledgling that manages to think up a way of avoiding being a lunch for a garden cat can only mate with another that has managed to do the same. The resources of the two of them might create the beginnings of a cat-avoidance dynasty. Intelligence is the increasingly aware and sophisticated existential feedback system, whereby the biological entities are able to detect and process increasingly complex assessments of their environment. It is an intelligence to evolve chemical detectors or eyes as much as it is to be able to process and analyse colour, form, numerical quantity, and to recognize oneself in a mirror. Intelligent behaviour ranges from the most primitive sensory awareness thru to the abstractions of science, mathematics and the arts. And of course... just like any individual life within it... nature is an event and as such has a beginning and an end, just like any other event.
A nature therefore, is an event during which intelligence develops in response to the survival pressures of avoiding becoming food...