The entire Logos, or the sum of Ideas, is called by Philo, entirely independent of Christianity, the true Son of God, while the realised world of Christian teaching passes as the second Son. If the first Logos is occasionally called the image or shadow of God, the world of sense is the image of the image, the shadow of the shadow. More logically expressed, God would be the _causa efficiens_, matter the _causa materialis_, the Logos the _causa instrumentalis_, while the goodness of God is sometimes added as the _causa finalis_. At the same time we also see here the difference between the working of the Jewish and Greek minds. In the Old Testament and in Philo, the Sophia or wisdom of God becomes a half mythological being, a goddess who is called the mother, and even the nurse,(17) of all beings. She bore with much labour out of the seed of God,(18) as Philo says, the only and beloved visible Son, that is to say, this Cosmos. This Cosmos is called by him the Son of God,(19) the only begotten,(20) while the first Logos is the first-born,(21) and as such often coincides with the Sophia and its activity.(22) He is also called the elder son,(23) and as such is distinguished from a younger son,(24) from the real, visible world. But this divine Sophia may not, according to Philo, any more than God Himself, come into direct contact with impure matter. According to him this contact occurs through the instrumentality of certain powers,(25) which in part correspond to the Greek Logoi, and which in his poetic language are also represented as angels.(26) Philo says in plain terms that the eternal Logoi, that is the Platonic ideas, are commonly called angels.