Since Epicureans thought that sensations could not deceive, sensations are the first and main criterion of truth for Epicureans. Even in cases where sensory input seems to mislead, the input itself is true and the error arises from our judgments about the input. For example, when one places a straight oar in the water, it appears bent. The Epicurean would argue that image of the oar, that is the atoms travelling from the oar to the observer's eyes, have been shifted and thus really do arrive at the observer's eyes in the shape of a bent oar. The observer makes the error in assuming that the image he or she receives correctly represents the oar and has not been distorted in some way. In order to not make erroneous judgments about perceivable things and instead verify one's judgment, Epicureans believed that one needed to obtain "clear vision" ("enargeia") of the perceivable thing by closer examination. This acted as a justification for one's judgements about the thing being perceived. "Enargeia" is characterized as sensation of an object that has been unchanged by judgments or opinions and is a clear and direct perception of that object.