“We must never make experiments to confirm our ideas, but simply to control them.”

The better educated we are and the more acquired information we have, the better prepared shall we find our minds for making great and fruitful discoveries.

A man of science rises ever, in seeking truth; and if he never finds it in its wholeness, he discovers nevertheless very significant fragments; and these fragments of universal truth are precisely what constitutes science.

Everything is poisonous, nothing is poisonous, it is all a matter of dose.

Effects vary with the conditions which bring them to pass, but laws do not vary. Physiological and pathological states are ruled by the same forces; they differ only because of the special conditions under which the vital laws manifest themselves.

Priestley said that each discovery we make shows us many others that should be made.

With the aid of these active experimental sciences man becomes an inventor of phenomena, a real foreman of creation; and under this head we cannot set limits to the power that he may gain over nature through future progress of the experimental sciences.

The minds that rise and become really great are never self-satisfied, but still continue to strive.

But while I accept specialization in the practice, I reject it utterly in the theory of science.

Science does not permit exceptions.

All the vital mechanisms, varied as they are, have only one object, that of preserving constant the conditions of life in the internal environment.

A fact in itself is nothing. It is valuable only for the idea attached to it, or for the proof which it furnishes.

Put off your imagination, as you put off your overcoat, when you enter the laboratory. Put it on again, as you put on your overcoat, when you leave.

In the philosophic sense, observation shows and experiment teaches.

In teaching man, experimental science results in lessening his pride more and more by proving to him every day that primary causes, like the objective reality of things, will be hidden from him forever and that he can only know relations.

Hatred is the most clear- sighted, next to genius.

Feeling alone guides the mind.

But in fact as Secretary of Homeland Security General John Kelly acknowledged at his confirmation hearing, walls and barriers alone are insufficient to insure security.

Books generally just confirm you in what you have, perhaps unwittingly, decided to do already.

We know that the Russian’s interfered in our election and they did it to benefit President Trump. The intelligence agencies confirmed that.

We must never make experiments to confirm our ideas, but simply to control them.

Reality does not conform to the ideal, but confirms it.

There is a logic of colors, and it is with this alone, and not with the logic of the brain, that the painter should conform.

It is difficult to lay aside a confirmed passion.

Truth is confirmed by inspection and delay; falsehood by haste and uncertainty.