I need to fact-check something for a book. The author says:
... to paraphrase Kant, “no fruit of the human tree has ever lacked for improvement.”
I can't find anything along these lines online in lists of Kant quotes.
Thanks so much!
It turns out to be a reference question.
Most common version = "Out of the crooked timber of humanity, no straight thing was ever made." (see https://en.wikiquote.org/wiki/Immanuel_Kant). It's from a relatively minor Kant work though I believe Allen Wood quotes it in Kant's Ethical Thought
There's also some things that reflect this sentiment in Anthropology and Religion within the Bounds of mere Reason, but the exact idea as you word it is not Kantian insofar as Kant thinks every human being has what they need to be moral -- and any inadequacy is incidental rather than endemic.