Psychology is concerned with studying and, hopefully, understanding human nature, behaviour and the workings of the brain. Our concern, here, is with the way in which psychology goes about its business. For better or worse, the approach of mainstream Western psychology to studying and understanding human behaviour is essentially a scientific one. When psychology first emerged from philosophy in the latter part of the 19th century, it was only natural for psychologists to borrow some of the techniques of the philosopher. One such technique was introspection.