Who loves or pursues or desires to obtain pain of itself, because it can procure great pleasure.
Pleasure is to be welcomed every pain avoided. But in certain claims of duty or the obligations.
To taken a trivial example, which of us ever undertakes it laborious physical exercise works.
Which is the same saying through shrinking from toil and pains. These cases are perfectly simple & easy to distinguish. In a free hour, when our power oft we like best.