First, then, I would draw attention to the fact that there is nothing wholly exceptional in such transformation with the sudden appearance of new powers and properties; but, on the contrary, it is in accordance with many analogies in the lower forces, and therefore _a priori_ not only credible but probable. For example, force and matter may be said to exist _now_ on several distinct planes raised one above another. There is a sort of taxonomic scale of force and matter. These are, 1, the plane of elements; 2, the plane of chemical compounds; 3, the plane of vegetal life; 4, the plane of animal life; and 5, the plane of rational and, as we hope, immortal life. Each plane has its own appropriate force and distinctive phenomena. On the first operates physical forces, producing physical phenomena only--for the operation of chemical affinity immediately raises matter to the next plane. On the second plane operates, in addition to physical, also chemical forces, producing all those changes by action and reaction, the study of which constitutes the science of chemistry. On the third plane, in addition to the two preceding forces, with their characteristic phenomena, operates also life-force, producing the distinctive phenomena characteristic of living things. On the fourth plane, in addition to all lower forces and their phenomena, operates also a higher form of life-force characteristic of animals, producing the phenomena characteristic of sentient life, such as sensation, consciousness, and will. On the fifth plane, in addition to all the preceding forces and phenomena, we have also the forces and phenomena characteristic of rational and moral life. Now, although there are doubtless great differences of level on each of these planes, yet there is a very distinct break between each. Although there are various degrees of the force characteristic of each, yet the difference between the characteristic forces is one of kind as well as of degree. Although energy by transmutation may take all these different forms, and thus does now circulate up and down through all these planes, yet the passage from one plane upward to another is not a gradual passage by sliding scale, but _at one bound_. When the necessary conditions are present, a new and higher form of force at once appears, _like a birth_ into a higher sphere. For example, when hydrogen and oxygen are brought together under proper conditions, water is born--a new thing with new and wholly unexpected properties and powers, entirely different from those of its components. When CO2, H2O, and NH3 are brought together under suitable conditions, viz., in the green leaves of plants, in the presence of sunlight, living protoplasm is then and there born, a something having entirely new and unexpected powers and properties. It is no gradual process but sudden, like birth into a higher sphere.