Modern psychology is an attempt to bring the methods of scientific investigation, which have proved immensely fruitful in other fields, to bear upon mental life and its problems. The human individual, the main object of study, is so complex an object, that for a long time it seemed doubtful whether there ever could be real science here; but a beginning was made in the nineteenth century, following the lead of biology and physiology, and the work of the investigator has been so successful that there is quite a respectable body of knowledge to assemble under the title of scientific psychology. Psychology: A Study Of Mental Life by prominent psychologist Robert S. Woodworth is an introduction into scientific psychology.