Commentary PARIS—In the heyday of Stalinist philosophising, one of the three so-called laws of dialectical materialism was that of the interpenetration of opposites. According to this “law,” there is never a perfectly sharp division between opposites, but rather internal connections between them as they ‘struggle’ with one another until some new stage or state of overcoming is reached, when the whole process begins again. Like the life of a twenty-four-hour city, the dialectic never ceases. Certainly, opposites can come to resemble one another, for example racism and antiracism. Both look at the world through the prism of race; both are powerful stimulants to hatred; both attribute characteristics not to individuals but to groups, in this case racial groups; both seek to impose their vision on the world, if necessary by force. Usually (according to the doctrine) one of the sides, or poles, of a contradiction is stronger than the other: …