Contributed by Jonathan Stevenson / David Humphrey’s visual and intellectual virtuosity — augmented by the smooth surface finality of meticulously applied acrylic paint — is such that he seems to accomplish everything he wants in a given painting. Each one in his current exhibition “I’m Glad We Had This Conversation,” at Fredericks & Freiser, stands as a cohesive essay — establishing a theme, teasing it out, and offering a witty take. If that sounds too neat and squared away for a mode of expression that is supposed to register some mystery and wonder, it is’t. There is constructive enigma in Humphrey’s purposeful, highly-wrought approach.