Each of us is armed with this touchstone of actuality; by applying it we decide that this sorry world of ours is actual and Utopia is a dream. As our… - Arthur Eddington

Relativity physics is especially interested in invariants, and it has discovered and named a few more. It is a common mistake to suppose that Einstein’s theory of relativity asserts that everything is relative. Actually, it says: 'There are absolute things in the world but you must look deeply for them. The things that first present themselves to your notice are for the most part relative'.

However closely we may associate thought with the physical machinery of the brain, the connection is dropped as irrelevant as soon as we consider the fundamental property of thought — that it may be correct or incorrect. … that involves recognising a domain of the other type of law — laws which ought to be kept, but may be broken.

The chairs and tables around us which broadcast to us incessantly those signals which affect our sight and touch cannot in their nature be like unto the signals or to the sensations which the signals awake at the end of their journey.