Everything in nature is the result of fixed laws.
If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find no such case.
Interpretation
What this quote means
Darwin asserts that all complex organs can be explained through gradual evolutionary changes.
In this quote, Charles Darwin emphasizes the foundational principle of his theory of evolution, which is that complex biological structures can be understood as the result of gradual changes over time, rather than arising suddenly or through any other means. He is expressing a commitment to finding evidence that can contradict his theory, yet he indicates his confidence that such evidence does not exist, thus reinforcing the validity of evolutionary explanations in biology.
Themes
In practice
Example use cases
In a classroom discussion about the principles of evolution, this quote could help illustrate the importance of gradual changes in organisms.
More from Charles Darwin
All quotes →The highest possible stage in moral culture is when we recognize that we ought to control our thoughts.
I am quite conscious that my speculations run beyond the bounds of true science....It is a mere rag of an hypothesis with as many flaw[s] & holes as sound parts.
We cannot fathom the marvelous complexity of an organic being; but on the hypothesis here advanced this complexity is much increased. Each living creature must be looked at as a microcosm--a little universe, formed of a host of self-propagating organisms, inconceivably minute and as numerous as the stars in heaven.
I have called this principle, by which each slight variation, if useful, is preserved, by the term of Natural Selection.
we are always slow in admitting any great change of which we do not see the intermediate steps
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