Paul Ehrlich

We must always be critical of our own assumptions.

The future of medicine depends on our ability to understand and manipulate biological processes.

The scientific community is a global enterprise.

The greatest challenges often lead to the greatest breakthroughs.

For the diseases of the poor, we need remedies which are cheap, easy to produce, and stable in tropical climates.

The strength of a chain is its weakest link.

Four G's: Geduld, Geschick, Glück, und Geld. (Patience, Skill, Luck, and Money.)

A drug is not a drug unless it has a selective action.

The aim of chemotherapy is to find substances which have a specific affinity for pathogenic organisms, a power of killing them, but which, at the same time, possess little or no affinity for the cells of the body.

I have invented nothing. I have only developed the ideas of others.

The physician must have a thorough knowledge of the natural sciences, and especially of chemistry.

From the standpoint of the parasite, the ideal host is one that does not die.

The first rule of intelligent tinkering is to save all the parts.

In the case of infectious diseases, we are dealing with a war between two organisms.

The side-chain theory is not a finished building, but a scaffolding which we hope will serve for the erection of a more solid structure.

A researcher needs not only ideas but also the means to realize them.

The task of therapy is to find means of correcting the pathological deviations of the body's chemistry.

Salvarsan is not the end, but the beginning.

The fight against syphilis is a fight for the health of the nation.

One must apply systematic, patient, and persistent work.