 Why is condition (iii) necessary? Why not say that knowledge is true belief? The standard answer is that to identify knowledge with true belief would be implausible because a belief might be true even though it is formed improperly. Suppose that William flips a coin, and confidently believes—on no particular basis—that it will land tails. If by chance the coin does land tails, then William’s belief was true; but a lucky guess such as this one is no knowledge. For William to know, his belief must in some epistemic sense be proper or appropriate: it must be  justified.[5]