(39.) If all things are matter, and if thought within me, as well as in other men, be no more than an effect of the arrangement of matter, how came any other idea, but that of material things into this world? Is matter able to produce so pure, so simple, so immaterial an idea as we have of spirit? How can matter be the origin of that which rejects and excludes such an idea from its very being? How can it be the cogitative principle in man, that is, that principle which convinces man he is not merely matter? (40.) There are beings of short duration, because they are made up of things varying much in their nature, and destructive to one another; there are others more lasting, because they are simpler, but they perish at last, being made up of several parts, into which they are divisible. That which thinks within me must naturally be permanent, as it is a pure being, free from all mixture and composition; there is no reason why it should perish; for what can corrupt or divide a simple being, in which are no parts? (41.) The soul sees colour through the organ of the eye, and hears sounds through the organ of the ear; but it may cease either from seeing or hearing when those senses or those objects are absent, and yet not cease from existing, because it is not exactly the soul that sees or hears; it is only that which thinks. Now, how can it cease from being such? Not for want of organs, since it has been proved it is not matter; nor for want of objects, whilst there is a God and eternal truths; it is therefore incorruptible. (42.) I cannot conceive the annihilation of a soul which God has filled with the idea of His infinite and all-perfect being.