Philosophy: greatest pleasure.

According to the Ethics of the Garden, philosophy=peace of mind, which is the greatest good. How can philosophy be considered a peace of mind? If philosophy is continually questioning what is right and asking for an explanation when is one's mind at ease? With philosophy the mind is continually learning and discovering the answers to the questions brought fourth. If the mind is working and digging to find meanings how can it be at peace? I can understand the greatest good because with the questions being brought to attention and answered truth is discovered. What could be better or a "greater good" than truth?