Change has consequently a double sense; one with reference to existence and another with reference to the Notion. When change is considered by the ancients, it is usually supposed to have to do with a change in what exists, and thus, for instance, inquiry would be made as to whether water can be changed through chemical action, such as heat, distillation, &c., into earth; finite chemistry is confined to this. But what is meant in all ancient philosophies is change as regards the Notion. That is to say, water does not become converted into air or space and time in retorts, &c. But in every philosophic idea, this transition of one quality into another takes place, _i.e._ this inward connection is shown in the Notion, according to which no one thing can subsist independently and without the other, for the life of nature has its subsistence in the fact that one thing is necessarily related to the other. We certainly are accustomed to believe that if water were taken away, it would indeed fare badly with plants and animals, but that stones would still remain; or that of colours, blue could be abstracted without harming in the least yellow or red. As regards merely empirical existence, it may easily be shown that each quality exists on its own account, but in the Notion they only are, through one another, and by virtue of an inward necessity. We certainly see this also in living matter, where things happen in another way, for here the Notion comes into existence; thus if, for example, we abstract the heart, the lungs and all else collapse. And in the same way all nature exists only in the unity of all its parts, just as the brain can exist only in unity with the other organs. 3. If the form is, however, only expressed in both its sides as condensation and rarefaction, it is not in and for itself, for to be this it must be grasped as the _absolute Notion_, and as an endlessly forming unity. What is said on this point by Aristotle (De Anima, I. 2, also 5) is this: “Thales seems, according to what is said of him, to consider the soul as something having movement, for he says of the loadstone that it has a soul, since it moves the iron.” Diogenes Laertius (I. 24) adds amber to this, from which we see that even Thales knew about electricity, although another explanation of it is that _ἤλεκτρον_ was besides a metal. Aldobrandini says of this passage in Diogenes, that it is a stone which is so hostile to poison that when touched by such it immediately hisses. The above remark by Aristotle is perverted by Diogenes to such an extent that he says: “Thales has likewise ascribed a soul to what is lifeless.” However, this is not the question, for the point is how he thought of absolute form, and whether he expressed the Idea generally as soul so that absolute essence should be the unity of simple essence and form.