When the province of physical theory was extended to encompass microscopic phenomena through the creation of quantum mechanics, the concept of consciousness came to the fore again. It was not possible to formulate the laws of quantum mechanics in a fully consistent way without reference to the consciousness.

... mathematics is the science of skillful operations with concepts and rules invented just for this purpose.

The simplicities of natural laws arise through the complexities of the language we use for their expression.

[T]he laws of quantum mechanics itself cannot be formulated ... without recourse to the concept of consciousness.

The enormous usefulness of mathematics in the natural sciences is something bordering on the mysterious and there is no rational explanation of it.

The optimist regards the future as uncertain.

The world is very complicated and it is clearly impossible for the human mind to understand it completely. Man has therefore devised an artifice which permits the complicated nature of the world to be blamed on something which is called accidental and thus permits him to abstract a domain in which simple laws can be found.