The word technique comes from the Greek word, téchnē, whose Latin cognate is ars. As often as we hear of surgery or of acoustic engineering or of any other technique, that it is an art, we also hear that it is a scientific art or technique. It is both art and science, in the sense that some techniques are scientifically attested, some not, as well as in the sense that every item of our contemplation has unique aspects, not given to science, as well as repeatable ones, subject to scientific investigation.