Tout est poison, rien n'est poison, tout est une question de dose. Everything is poisonous, nothing is poisonous, it is all a matter of dose.
Man does not limit himself to seeing; he thinks and insists on learning the meaning of phenomena whose existence has been revealed to him by observation. So he reasons, compares facts, puts questions to them, and by the answers which he extracts, tests one by another. This sort of control, by means of reasoning and facts, is what constitutes experiment, properly speaking; and it is the only process that we have for teaching ourselves about the nature of things outside us.
Interpretation
What this quote means
This quote emphasizes the importance of observation and reasoning in understanding the world around us.
Claude Bernard highlights the human capacity for critical thinking and inquiry through the process of observation, reasoning, and experimentation. He suggests that true understanding comes not just from seeing but from actively engaging with our observations, analyzing them, and drawing conclusions based on the reasoning of facts. This methodical approach is central to scientific exploration and helps uncover the nature of external phenomena.
Themes
In practice
Example use cases
In a classroom setting, a teacher can use this quote to encourage students to engage in critical thinking during science experiments.
More from Claude Bernard
All quotes →When a physician is called to a patient, he should decide on the diagnosis, then the prognosis, and then the treatment. ... Physicians must know the evolution of the disease, its duration and gravity in order to predict its course and outcome. Here statistics intervene to guide physicians, by teaching them the proportion of mortal cases, and if observation has also shown that the successful and unsuccessful cases can be recognized by certain signs, then the prognosis is more certain.
The goal of scientific physicians in their own science ... is to reduce the indeterminate. Statistics therefore apply only to cases in which the cause of the facts observed is still indeterminate.
Theories are like a stairway; by climbing, science widens its horizon more and more, because theories embody and necessarily include proportionately more facts as they advance.
True science teaches us to doubt and, in ignorance, to refrain.
Now, a living organism is nothing but a wonderful machine endowed with the most marvellous properties and set going by means of the most complex and delicate mechanism.
Similar quotes
If there is anything that can bind the heavenly mind of man to this dreary exile of our earthly home and can reconcile us with our fate so that one can enjoy living,-then it is verily the enjoyment of the mathematical sciences and astronomy.
In spite of the opinions of certain narrow-minded people who would shut up the human race upon this globe, we shall one day travel to the Moon, the planets, and the stars with the same facility, rapidity and certainty as we now make the ocean voyage from Liverpool to New York.
Everybody who's a physician, who makes vaccines, who wants to find the cure for cancer. Everybody who wants to do any medical good for humankind got the passion for that before he or she was 10.
The role of radiologists will evolve from doing perceptual things that could probably be done by a highly trained pigeon to doing far more cognitive things.
There can sometimes be this fear among laypeople: 'I don't understand everything in science perfectly, so I just can't say anything about it.' I think it's good to know that we scientists are also confused some of the time.
The main reason why people should care about research in fundamental physics is the same reason they care about astronomy and cosmology. People, children, want to know what we're made out of, how it works, and why the universe is the way it is.