God's Essence is Absolutely Simple
Now, if God were of any causes, internal or external, any principles antecedent or superior to him, he could not be so absolutely first and independent. Were he composed of parts, accidents, manner of being, he could not be first; for all these are before that which is of them, and therefore his essence is absolutely simple.
John Owen, Vindiciae Evangelicae, "Mr Biddle’s Preface Briefly Examined", 72