Hello, everyone !
In the nutshell Buddhism is about virtues, concentration and
discernment (siila, samaadhi, and pa~n~naa). One who has developed
discernment fully comprehends the Four Noble Truths.
The following dialogue connects discernment with direct knowledge.
Ven. Maha Kotthita : "With what does one know a quality that can be
known?"
Ven. Sariputta: "One knows a quality that can be known with the eye of
discernment."
Ven. Maha Kotthita : "And what is the purpose of discernment?"
Ven. Sariputta: "The purpose of discernment is direct knowledge, its
purpose is full comprehension, its purpose is abandoning."
[MN 43 Mahavedalla Sutta: The Greater Set of Questions-and-Answers ]
http://www.accesstoinsight.org/tipitaka/mn/mn.043.than.html#t-1
Best wishes.