Similarly, we can have knowledge of God's properties, even of His unique properties, by virtue of the fact that these properties have perceptible effects. Nothing prevents us from reasoning from effects to very exotic, unfamiliar kinds of causes. Inferential knowledge can invole the inference of imperceptible causes that are very dissimilar to anything we can perceive. The way of escape is through the doctrine of analogy, developed by Aquinas and based on Aristotle's metaphysics. Simply put, analogy is sameness without similarity.
Analogy is a relation between two cases of predication or attribution of a property.
For example, if I say that oak trees are alive, and tigers are alive, these two predications are analogous. Oak trees and tigers share the very same property, life, but life is realized in these things in two radically different ways. The life of an oak tree bears little resemblance to the life of a tiger, beyond the bare fact that both are instances of life. Similarly, if we say that humans are intelligent and God is intelligent, we are attributing intelligence analogously. Similarly, 'God creates' and 'Man creates' are analogous attributions.