Max Planck

The quantum hypothesis is not a hypothesis; it is a fact.

I was never a revolutionary. I just wanted to do something useful.

The soul is the seat of all knowledge and all truth.

The greatest obstacle to discovery is not ignorance, but the illusion of knowledge.

It was a dark and stormy night...

The spiritual world is the true reality.

The quantum of action is the universal constant that determines the size of the smallest units of energy.

The scientific method is a never-ending process of refinement and correction.

The scientist's highest aim is to find the truth.

The whole development of science is nothing but a continuous struggle to escape from the magic of the senses.

The human mind is capable of understanding the universe.

Physics is the study of nature, and nature is the manifestation of God.

The greatest discovery of all time is that man can change his future by merely changing his attitude.

Science and religion are not antagonistic; they are complementary.

The world needs men who can think for themselves, and not just repeat what they have been taught.

The constant changes in the scientific worldview show how important it is to remain open to new ideas.

There can be no such thing as a 'pure' science, as science is always influenced by the human mind.

The history of science shows that even the most firmly established theories can be overturned by new discoveries.

The true scientist is a man who is always asking questions, and never satisfied with the answers.

The human mind is the most complex and mysterious thing in the universe.