107

Logic IV. 116
arguments whether we bring in Causity or not this argument about the line parallels it. For Plato defines the soul and his argument however understood consistss in this that the cessaton of the soul would be contrary to the definition of it. That is it cannot cease to be without ceasing to be a soul. Now it is true of a line that it can not come to a termination without, at that termination losing the essential character of a line. That this is a valid argument within its proper limits is show by the fact that from this is rightly follows that no line in analytical geometry can have a stopping place. To apply this argument actual existence and maintain that no real line could be terminated because no line is terminated without infringement of its essential character would be if and rightly apprehend is precise parallel to the Phaedran argument for the immortality of the soul. Arrived as that period let us