Aristotle’s distinction between practical knowledge and theoretical knowledge

Clarify as much as possible Aristotle’s distinction between practical knowledge and theoretical knowledge.  Does an understanding of this distinction help account for why persons who know certain habits or behaviors are harmful, still persist in those behaviors?

From a practical point of view Aristotle understood that habits learned at an early age, both good and bad, will shape the character of an individual.  He makes it quite clear that those habits learned are crucial towards the development of moral virtue.  For he states, “It makes no small difference, then, whether we form habits of one kind or of another from our very youth; it makes great difference, or rather all the difference.”  He believed that virtues are adapted by nature and they made perfect by habit.  If habits learned in youth are devoid of righteousness, then an individual will exhibit behaviors contrary to the virtues of moral integrity as an adult.  He made this evident by stating, “Human good turns out to be activity of the soul in accordance with virtue.”

Theoretically Aristotle judged that to reach the highest virtue one must contemplate that which is best for us.  This could be achieved by sound reason, noble conduct, or by divine inspiration.  To even reach this pinnacle of moral virtue one must have had habits learned from an early age.  You cannot contemplate the highest level of good without having been taught the essence of good.  You would not have the ability to contemplate truth as evidenced by Aristotle’s statement: “For nothing arises from it apart from the contemplating, while from practical activities we gain more or less apart from the action.”