THREE:It will be seen from the foregoing passage how strong a hold the old Greek notion of an encircling limit had on the mind of Aristotle, and how he transformed it back from the high intellectual significance given to it by Plato into its original sense of a mere space-enclosing figure. And it will also be seen how he credits his spheres with a full measure of that moving power which, according to his rather unfair criticism, the Platonic Ideas did not possess. His astronomy also supplied him with that series of graduated transitions between two extremes in which Greek thought so much delighted. The heavenly bodies mediate between God and the earth; partly active and partly passive, they both receive and communicate the moving creative impulse. The four terrestrial elements are moved in the various categories of substance, quantity, quality, and place; the aether moves in place only. God remains without variableness or shadow of a change. Finally, by its absolute simplicity and purity, the aether mediates between the coarse matter perceived by our senses and the absolutely immaterial Nous, and is itself supposed to be pervaded by a similar gradation of fineness from top to bottom. Furthermore, the upper fire, which must not be confounded with flame, furnishes a connecting link between the aether and the other elements, being related to them as Form to Matter, or as agent to patient; and, when the elements are decomposed into their constituent qualities, hot and cold occupy a similar position with regard to wet and dry.These divisions of machinery will next be treated of separately, with a view of making the classification more clear, and to explain the principles of operation in each division. This dissertation will form a kind of base upon which the practical part of the treatise will in a measure rest. It is trusted that the reader will carefully consider each proposition that is laid down, and on his own behalf pursue the subjects farther than the limits here permit.
1 5～2岁是儿童分享行为能力发展的关键期，父母要抓住这个时期，在日常生活中加以引导。教宝宝怎样与他人分享自己喜欢的东西。
