Hermann von Helmholtz

Heat, light, electricity, and magnetism are different manifestations of the same force.

Philosophy is the science of the possible.

The human mind is not a passive receiver but an active interpreter of sensations.

Progress in science depends on new techniques, new discoveries, and new ideas, probably in that order.

Life is a perpetual instruction in causality.

The artist and the scientist both seek truth, but by different paths.

In science, we must be bold in hypothesis but cautious in conclusion.

The laws of nature are the thoughts of God written in the language of mathematics.

Observation is the foundation of science, but imagination is its soul.

Happiness is the meaning and purpose of life, the whole aim and end of human existence.

The ear does not hear sounds, but the mind interprets vibrations as music.

Science advances one funeral at a time.

To know the true nature of man, study his science.

Energy is eternal delight.

The physicist's greatest tool is not the instrument, but the trained mind.

In the realm of ideas, there are no boundaries but those we impose.

The secret of genius is to carry the spirit of the child into old age.

Light is the purest form of energy, revealing the hidden world.

Doubt is the origin of wisdom.

The harmony of the world is made manifest in the uniformity of nature's laws.