TWO:Aristotle next takes the Idea of Substance and subjects it to a fresh analysis.243 Of all things none seem to possess so evident an existence as the bodies about us��plants and animals, the four elements, and the stars. But each of these344 has already been shown to consist of Form and Matter. A statue, for instance, is a lump of bronze shaped into the figure of a man. Of these two constituents, Matter seems at first sight to possess the greater reality. The same line of thought which led Aristotle to place substance before the other categories now threatens to drive him back into materialism. This he dreaded, not on sentimental or religious grounds, but because he conceived it to be the negation of knowledge. He first shows that Matter cannot be the real substance to which individuals owe their determinate existence, since it is merely the unknown residuum left behind when every predicate, common to them with others, has been stripped off. Substance, then, must be either Form alone or Form combined with Matter. Form, in its completest sense, is equivalent to the essential definition of a thing��the collection of attributes together constituting its essence or conception. To know the definition is to know the thing defined. The way to define is to begin with the most general notion, and proceed by adding one specific difference after another, until we reach the most particular and concrete expression. The union of this last with a certain portion of Matter gives us the individual Socrates or Callias. There are no real entities (as the Platonists pretend) corresponding to the successive stages of generalisation, biped, animal, and so forth, any more than there are self-existing quantities, qualities, and relations. Thus the problem has been driven into narrower and narrower limits, until at last we are left with the infim? species and the individuals contained under them. It remains to discover in what relation these stand to one another. The answer is unsatisfactory. We are told that there is no definition of individuals, and also that the definition is identical with the individual.244 Such, indeed, is the conclusion necessarily resulting from Aristotle��s repeated declarations that all knowledge is of345 definitions, that all knowledge is of something really existing, and that nothing really exists but individual things. Nevertheless, against these we have to set equally strong declarations to the effect that knowledge is of something general, not of the perishing individuals which may pass out of existence at any moment. The truth is, that we are here, as Zeller has shown,245 in presence of an insoluble contradiction, and we must try to explain, not how Aristotle reconciled it with itself, for that was impossible, but how he reconciled himself to it.6

TWO:Wind-power, aside from the objections of uncertainty and irregularity, is the cheapest kind of motive-power. Steam machinery, besides costing a large sum as an investment, is continually deteriorating in value, consumes fuel, and requires continual skilled attention. Water-power also requires a large investment, greater in many cases than steam-power, and in many places the plant is in danger of destruction by freshets. Wind-power is less expensive in every way, but is unreliable for constancy except in certain localities, and these, as it happens, are for the most part distant from other elements of manufacturing industry. The operation of wind-wheels is so simple and so generally understood that no reference to mechanism need be made here. The force of the wind, moving in right lines, is easily applied to producing rotary motion, the difference from water-power being mainly in the comparative weakness of wind currents and the greater area required in the vanes upon which the wind acts. Turbine wind-wheels have been constructed on very much the same plan as turbine water-wheels. In speaking of wind-power, the propositions about heat must not be forgotten. It has been explained how heat is almost directly utilised by the steam-engine, and how the effect of heat is utilised by water-wheels in [42] a less direct manner, and the same connection will be found between heat and wind-wheels or wind-power. Currents of air are due to changes of temperature, and the connection between the heat that produces such air currents and their application as power is no more intricate than in the case of water-power.

TWO:CHAPTER XLVI. HETTY LEARNS SOMETHING.Aeternas quoniam poenas in morte timendum.��158