Original from the beginning of the 3rd inner chapter and my own provisional translation followed by 4 others (in the same order):
Cultivando o Anfitrião da Vida
The Preservation of Life (Lin Yutang)
Opinions on Nurturing Life (Nina Correa)
The Secret of Caring for Life (Burton Watson)
Nourishing the Lord of Life (James Legge)
Nossa vida tem um limite, mas o conhecimento é ilimitado.
Human life is limited, but knowledge is limitless.
There are limits in our lives, but there are no limits to knowledge.
YOUR LIFE HAS A LIMIT but knowledge has none.
There is a limit to our life, but to knowledge there is no limit.
Usar o limitado para buscar o ilimitado é perigoso;
To drive the limited in pursuit of the limitless is fatal;
Using what's limited to try to catch up with what's unlimited can only bring trouble.
If you use what is limited to pursue what has no limit, you will be in danger.
With what is limited to pursue after what is unlimited is a perilous thing;
What you call foolish is actually 殆已.
殆 may mean "dangerous", "perilous", "to endanger", but also "almost", "probably", "only". According to Chinese Etymology: precarious / dangerous / danger / perilous / tired / afraid / nearly / almost / only / merely / even
So, it looks even worse than "foolish". I partially agree with the interpretation of Fatto Lee. But I don't think "rationality" is a state to be avoided. It's part of human nature. I think taoism is more against an excess of reason, reason disconnected of emotion, of balance, spontaneity and common sense. As the Dao De Jing emphasizes: "flexibility overcomes rigidity".