KJV:
And I gave my heart to know wisdom, and to know madness and folly: I perceived that this also is vexation of spirit.
NASB:
And I set my mind to know wisdom and to know madness and folly; I realized that this also is striving after wind.
KJV:
I sought in mine heart to give myself unto wine, yet acquainting mine heart with wisdom; and to lay hold on folly, till I might see what was that good for the sons of men, which they should do under the heaven all the days of their life.
NASB:
I explored with my mind how to stimulate my body with wine while my mind was guiding me wisely, and how to take hold of folly, until I could see what good there is for the sons of men to do under heaven the few years of their lives.
KJV:
And I turned myself to behold wisdom, and madness, and folly: for what can the man do that cometh after the king? even that which hath been already done.
NASB:
So I turned to consider wisdom, madness and folly; for what will the man do who will come after the king except what has already been done?
KJV:
Then I saw that wisdom excelleth folly, as far as light excelleth darkness.
NASB:
And I saw that wisdom excels folly as light excels darkness.