And again: ‘There is nowhere a balanced judgment and a balanced action, but always a cancelling of one another by opposite errors. Men pair off in insane parties, as Emerson puts it.’
The reader will now begin to understand the sense in which polarity applies to these complex conditions of an advanced evolution.
To return, however, from this digression to the point at which it began, viz. the origin of life, we have to show how the law of polarity prevails in the organic as well as in the inorganic world. In the first place the material to which all life is attached, from the speck of protoplasm to the brain of man, is strictly a chemical product of atoms and molecules bound together by the same polar laws as those of inorganic matter.
In like manner all the essential processes by which life lives, moves, and has its being, are equally mechanical and chemical. If the brain, receiving a telegram from without through the optic nerve, sends a reply along another nerve which liberates energy stored up in a muscle and produces motion, the messages are received and transmitted like those sent by a voltaic battery along the wires of a telegraph, and the energy is stored up by the slow combustion of food in oxygen, just as that of the steam-engine is produced by the combustion of coal. All this is mechanical, inorganic, and therefore polar.
But when we come to the conditions of life proper, we find the influence of polarity mainly in this: that as it develops from simpler into more complex forms, it does so under the law of developing contrasts or opposite polarities, which are necessary complements of each other’s existence. Thus, as we ascend in the scale of life, we find two primitive polarities developed: that of plant and animal, and that of male and female.
Contrast in developed life—Plants producers, animals consumers—Differences disappear in simple forms—Zoophytes—Protista—Nummulites—Corals—Fungi—Lichens—Insectivorous plants—Geological succession—Primary period, Algæ and Ferns—Secondary period, Gymnosperms—Tertiary and recent, Angiosperms—Monocotyledons and Dicotyledons—Parallel evolution of animal life—Primary, protista, mollusca, and fish—Secondary, reptiles—Tertiary and recent, mammals.
