Whitman on wisdom

Now I see the secret of the making of the best persons,
It is to grow in the open air and to eat and sleep with the earth.

Here a great personal deed has room,
(Such a deed seizes upon the hearts of the whole race of men,
Its effusion of strength and will overwhelms law and mocks all
    authority and all argument against it.)

Here is the test of wisdom,
Wisdom is not finally tested in schools,
Wisdom cannot be pass'd from one having it to another not having it,
Wisdom is of the soul, is not susceptible of proof, is its own proof,
Applies to all stages and objects and qualities and is content,
Is the certainty of the reality and immortality of things, and the
    excellence of things;
Something there is in the float of the sight of things that provokes
    it out of the soul.

Now I re-examine philosophies and religions,
They may prove well in lecture-rooms, yet not prove at all under the
    spacious clouds and along the landscape and flowing currents.

Here is realization,
Here is a man tallied--he realizes here what he has in him,
The past, the future, majesty, love--if they are vacant of you, you
    are vacant of them.

Walt Whitman Song of the Open Road