It is not always the magnitude of the differences observed between species that must determine specific distinctions, but the constant preservation of those differences in reproduction.
Interpretation
The importance of how differences between species are maintained through reproduction is more significant than their size.
Jean-Baptiste Lamarck emphasizes that while observable differences between species can vary greatly, it is the consistency in how these differences are passed on through reproduction that truly defines the uniqueness of each species. This highlights the role of heredity and reproduction in evolutionary biology, suggesting that the stability of traits is fundamental to the identification of species rather than just the extent of their differences.
In practice
In a biology class discussing evolution, this quote could be used to explain how traits are inherited.
Now this circumscribed power, which we have scarcely examined, scarcely studied, this power to whose actions we nearly always attribute an intention and a goal, this power, finally, that always does necessarily the same things in the same circumstances and nevertheless does so many and such admirable ones, is what we call 'nature' .
All knowledge that is not the real product of observation, or of consequences deduced from observation, is entirely groundless and illusory.
It is not enough to discover and prove a useful truth previously unknown, but that it is necessary also to be able to propagate it and get it recognized.
Many people have the impression that there is significant scientific disagreement about global climate change. It's time to lay that misapprehension to rest. There is a scientific consensus on the fact that Earth's climate is heating up and human activities are part of the reason. We need to stop repeating nonsense about the uncertainty of global warming and start talking seriously about the right approach to address it.
O telescope, instrument of much knowledge, more precious than any sceptre!
People are going to buy cheap fertilizer so they can grow enough crops to feed themselves, which will be increasingly difficult with climate change.
The scientist is not responsible for the laws of nature. It is his job to find out how these laws operate. It is the scientist's job to find the ways in which these laws can serve the human will. However, it is not the scientist's job to determine whether a hydrogen bomb should be constructed, whether it should be used, or how it should be used. This responsibility rests with the American people and with their chosen representatives.
The Earth is not 6,000 or 10,000 years old. It's not. And if that conflicts with your beliefs, I strongly feel you should question your beliefs.
Experimentation is the least arrogant method of gaining knowledge. The experimenter humbly asks a question of nature.
Subscribe for the occasional hand-picked quote. No noise.