And this is God’s art of expression.  We can behold nothing pure; and all that we see is compounded and mixed.  Nature stands related to us at a certain angle, and a little remove either way—­back toward its grosser side, or up toward its ideal tendency—­would place it beyond our ken.  It is like the rainbow, which is a partial and an incomplete development,—­ pure white light split up and its colors detached and dislocated, and which is seen only from a certain stand-point.

We remark, therefore, that all things are made of one stuff, and on the principle that a difference in degree produces a difference in kind.  From the clod and the rock up to the imponderable, to light and electricity, the difference is only more or less of selection and filtration.  Every grade is a new refinement, the same law lifted to a higher plane.  The air is earth with some of the coarser elements purged away.  From the zooephyte up to man, more or less of spirit gives birth to the intervening types of life.  All motion is but degrees of gravitating force; and the thousand colors with which the day paints the earth are only more or less of light.  All form aspires toward the circle, and realizes it more or less perfectly.  By more or less of heat the seasons accomplish their wonderful transformations on the earth and in the air.  In the moral world, the eras and revolutions that check history are only degrees in the development of a few simple principles; and the variety of character that diversifies the world of men and manners springs from a greater or less predominance of certain individual traits.

This law of degrees, pushed a little farther, amounts to detachment and separation, and gives birth to contrast and comparison.  This is one aspect in which the law manifests itself in the individual.  The chairs and the pictures must come out from the wall before we can see them.  The tree must detach itself from the landscape, either by form or color, before it becomes cognizable to us.  There must be irregularity and contrast.  Our bodily senses relate us to things on this principle; they require something brought out and disencumbered from the mass.  The eye cannot see where there is no shade, nor the hand feel where there is no inequality of surface, nor the palate taste where there is no predominance of flavor, nor the ear hear where there is no silence.  Montaigne has the following pertinent passage, which also comes under this law:—­“Whoever shall suppose a pack-thread equally strong throughout, it is utterly impossible it should break; for where will you have the breaking to begin?  And that it should break altogether is not in Nature.”

The palpableness and availableness of an object are in proportion as it is separated from its environments.  We use water as a motive power by detaching a part from the whole and placing ourselves in the way of its tendency to unite again.  All force and all motion are originated on this principle.  It is by gravity that we walk and move and overcome resistance, and, in short, perform all mechanical action; yet the condition is that we destroy the settled equilibrium of things for the moment, and avail ourselves of the impulse that restores it again.  The woodman chops by controlling and breaking the force which he the next moment yields to.