 Those who defend either the argument from analogy or from best explanation are firmly of the view that any knowledge we may have of other minds (or any justification there may be for our belief in them) must be indirect. They accept that, while our knowledge of our own mental states is direct, our knowledge of the mental states of others must proceed by reasoning from what we observe—the other’s behavior—to what we cannot observe—the other’s mental  states.[2]  The idea that the mind of another is not directly observable is one that seems common to many philosophers. As early as the fifth century AD, St. Augustine writes: “For even when a living body is moved, there is no way opened to our eyes to see the mind, a thing which cannot be seen by the eyes…” (De Trinitate 140; cf. Descartes 1641, Second Meditation; and Berkeley 1710, Principle 148) The idea that we should have direct knowledge of another’s mental states has also come under fire more recently by Colin McGinn, who writes that direct perceptual reports specifying the mental states of another “seem definitely wrong” (1984: 123, n. 2; cf. Plantinga 1966: 441).