He can choose and act for the benefit of the others, which will result in happiness and pleasure besides the perfection of the world. In particular Leibniz promotes the study of nature. By understanding the laws or the mechanisms of divine invention, we shall perfect ourselves far more than by merely following the constructions invented by men. Leibniz's practical conception of science resembles the one adopted by Francis Bacon. Whereas Bacon thought that the theoretical sciences result in practical applications, Leibniz considered all the sciences as the same - the difference is only in the point of view from which it is observed.
Ethics is just as demonstrative a science as the natural sciences.
And practical philosophy is a combination of ethics and politics. In English classical humanism there was a strong emphasis on the common good. The main aim of human life was said to be the advancement of the common good which could only be attained by a relentless pursuit of a virtuous vita activa, active life. The argument underlying in this was that the common good could not materialize unless everyone was fully committed to promote this aim by exercising the full range of civic virtues. Education was also an important element of these programs.