Space is a functional entity, presupposed by rational beings, whenever real entities are envisaged. Being a functional entity, space has no structure or form. It can neither physically act nor is able to undergo physical actions. By realising a real entity that fills the entire space as an all-encompassing universal medium, the formless space can be replaced with a structured real entity. This real entity will have positive existence and at the same time, it can have all properties currently assigned to space or to other imaginary entities like; different types of aether, imaginary particles or various types of fields. No actions can be performed at a distance through empty space. An all-encompassing medium is essential to facilitate (apparent) physical actions between matter bodies at a distance. Aether, used in aether-theories is too vague and fails to describe many physical actions of matter bodies, logically. 'Hypothesis on MATTER' envisages an all-encompassing medium, which has only one type of real (postulated) constituent particles and definite properties. Envisaging a universal medium, as described in the concept, helps to logically explain all physical phenomena, related to matter.