  As before, there are two main alternative readings of 151–187: the Unitarian and the Revisionist. On the Unitarian reading, Plato’s purpose is to salvage as much as possible of the theories of Protagoras and Heracleitus (each respectfully described as ou phaulon: 151e8, 152d2). Plato’s strategy is to show that these theories have their own distinctive area of application, the perceptible or sensible world, within which they are true. However, the sensible world is not the whole world, and so these theories are not the whole truth. We get absurdities if we try to take them as unrestrictedly true. To avoid these absurdities it is necessary to posit the intelligible world (the world of the Forms) alongside the sensible world (the world of perception). When this is done, Platonism subsumes the theories of Protagoras and Heracleitus as partial truths. On this reading, the strategy of the discussion of D1 is to transcend Protagoras and Heracleitus: to explain their views by showing how they are, not the truth, but parts of a larger truth. In the process the discussion reveals logical pressures that may push us towards the two-worlds Platonism that many readers, e.g., Ross and Cornford, find in the Republic and Timaeus.