Ideæ rerum singularium sive modorum non existentium ita debent comprehendi in Dei infinita idea ac rerum singularium sive modorumessentiæ formales in Dei attributis continentur.
English (Elwes 1883)
The ideas of particular things, or of modes, that do not exist, must be comprehended in the infinite idea of God, in the same way as the formal essences of particular things or modes are contained in the attributes of God.
Modern English
The ideas of singular things, or of modes, that do not exist must be comprehended in God's infinite idea in the same way that the formal essences of those singular things or modes are contained in the attributes of God.