We live in an age when humanity believes in itself. It believes in itself very thoroughly indeed. It is the beginning and the end to itself, its own solution to every problem.
Humanity knows that philosophy was made by it, and religion was made by it, and society was made by it. In fact, reality was made by it.
For (thus runs the reasoning) the agreement of a multiplicity of persons is the criterion we adopt for reality. There is no other criterion for determining reality. There is no other sense in which the word ‘reality’ can be used. Therefore reality is what a collection of people agree to call by this name.
from The Decline and Fall of Science