Observe, then, that likeness is one thing; image another. For example, the horse, the ox, or other dumb animal may have a certain likeness to man; but the image of man is borne by none but a human being. Man eats, so does the horse; here is a certain likeness, a certain something common to creatures of diverse moulds. But the image of 3man is only borne by some human being, some being of selfsame nature with that man whose image he is. Image, therefore, is of a higher order than likeness.
God's Likeness, then, may be attained by us in this way; if, musing on Him as the Good, we study to be good; if, owning Him the Just, we strive to be just; if, contemplating Him the Merciful, we make endeavours after mercy.
St. Anselm, Book of Meditations and Prayers