The philosophers of ancient Greece understood this, and it is unlikely that anyone would challenge this today.
Logic seems to have emerged from dialectics; the earlier philosophers made frequent use of concepts like reductio ad absurdum in their discussions, but never truly understood the logical implications.
In the Republic, the philosopher must understand the Idea of Justice to live a just life or to organize and govern a just state.
Even our wisest philosophers do not fully understand its nature.
Past philosophers had understood reference to be tied to words themselves.
It was this presentation which Jewish philosophers such as Moses Narboni and Gersonides understood to be Averroes'.
"Shortly before his death [Bohr] complained that no professional philosopher had ever understood his doctrine of complementarity."
Of course, philosophers from Plato to Rousseau have understood the crucial importance of child rearing, but they would have hardly trusted the important parts of it to female mothers.
Belike 'tis some philosopher With words too big to understand himself.
The French political philosopher Benjamin Constant understood the connection.