I communed with my own heart, saying, Lo, I have come to greatness, and have gotten more wisdom than all they that have been before me in Jerusalem: yea, my heart had great experience of wisdom and knowledge.

I sought in my heart to give myself unto wine, yet acquainting my heart with wisdom; and to lay hold on folly, till I might see what was good for the sons of men, which they should do under heaven all the days of their life.

And whatsoever my eyes desired I kept not from them, I withheld not my heart from any joy; for my heart rejoiced in all my labor: and this was my reward of all my labor.

Then said I in my heart, As it happens to the fool, so it happens even to me; and why was I then more wise? Then I said in my heart, that this also is vanity.

The heart of the wise is in the house of mourning; but the heart of fools is in the house of mirth.

This is an evil among all things that are done under the sun, that there is one event unto all: yea, also the heart of the sons of men is full of evil, and madness is in their heart while they live, and after that they go to the dead.

A wise man's heart is at his right hand; but a fool's heart at his left.

Rejoice, O young man, in your youth; and let your heart cheer you in the days of your youth, and walk in the ways of your heart, and in the sight of your eyes: but know that for all these things God will bring you into judgment.