Ludwig Boltzmann

Who, then, is to decide what is true and what is false? The ultimate court of appeal is observation and experiment, not the doctrines of men, however learned or venerable.

The second law of thermodynamics holds, I think, only with a certain degree of probability.

Entropy is not a measure of disorder, but rather a measure of the number of ways a system can be arranged.

The struggle for existence in the organic world is nothing but a struggle for matter in motion.

I am convinced that the particle theory will in the end be generally accepted.

The world is not deterministic, but probabilistic.

Atoms exist; that is an article of faith for the physicist.

The laws of thermodynamics may be asserted when the theory of probability is applied to a great number of molecules.

Life can only be understood backwards; but it must be lived forwards.

The deepest pain I have suffered nobody will ever understand.

In my opinion, a scientist's life is the most beautiful.

The molecule is the bridge between the inorganic and the organic world.

Probability is the guide of life.

The universe tends towards maximum entropy, yet life defies it temporarily.

Experiment without theory is blind, but theory without experiment is mere intellectual play.

I have always found that the less I know about a subject, the more confidently I can discuss it.

The physicist's greatest joy is to see theory confirmed by experiment.

Thermodynamics is the mechanics of heat.

The concept of equilibrium is fundamental to understanding irreversible processes.

Science advances one funeral at a time.