“It is always tempting to say that this is not a good time for ideas. Though people hold them or dismiss them, promote them or disparage them, ideas often seem unstable. Often we think we are debating an idea only to discover that it no longer means what we thought it meant. We proclaim our affection for equality, autonomy, liberation, authenticity only to find that the meanings of those words and the concepts they name have changed into something unrecognizable.”