The ecological model makes sense only in so far as these qualitative elements of environment are given a reality as real as the material objects around us. (religion-online.org)
The idea comes partly from evolutionary theories that suggest we will stay interested and alert if we have a sense that there are elements of our environment left to discover. (discovermagazine.com)
These are e.g. types of blocks (materials) available only here and special elements of environment. (gamepressure.com)