Irreducibility

The principle of Irreducibility, in philosophy, has the sense that a complete account of an entity will not be possible at lower levels of explanation and which has novel properties beyond prediction and explanation. Another way to state this is that Occam's razor requires the elimination of only those entities that are unnecessary, not as many entities as could conceivably be eliminated. Lev Vygotsky provides the following illustration of the idea, in his Thought and Language: