This science considers how men act for ends. He does this on account of his facilities of intellect and will, which seek as their ends truth and goodness, respectively. There are two types of goods: activities and things produced. Different goods are subordinated one to the other and ultimately to "architectonic" goods which are goods for the sake of which all other goods - be they either activities or things produced - are sought.
When the practice of the faith become as so many chains, weighing us down rather than lifting us up, it can be useful to recall the bare minimum to be a practicing Catholic.