Aquinas addresses the virtue of perseverance and the vices opposed to perseverance in Q.137[0] and Q.138[1] of the Summa, respectively. A virtue here is "a habit that directs us to do something well, or to omit something". Perseverance allows us to avoid forsaking "a good on account of long endurance of difficulties and toils".
As a virtue, it holds the mean between the errors that flank it on either side, avoiding effeminacy and delicacy on the one hand, and pertinacity on the other.
Effeminacy "withdraws from good on account of sorrow caused by lack of pleasure, yielding as it were to a weak motion", while delicacy "is a kind of effeminacy", but while effeminacy "regards lack of pleasures [...] delicacy regards the cause that hinders pleasure, for instance toil". In other words, effeminacy shrinks from things, because of the lack of pleasure, while delicacy shrinks on account of the discomfort caused.
Pertinacity holds on "impudently, as being utterly tenacious". It resists course correction.
Modern readers seem to misinterpret writings by virtue ethicists as self help, perhaps because much of modern "philosophical" discourse is just disguised therapy books.
These are descriptive, not prescriptive, when Aquinas says what perseverence means he doesn't tell you what to do to be virtuous, but what the virtue in itself is.
Although there are some prescriptions in the Summa (see Ia IIae Q38 as a prime example), Aquinas mostly left the study of the building of virtue to other writers, as it is a secondary matter.
Yes, as the aim is scientific (in the classical sense of the term), but he would be the first to reject the fact/value dichotomy. Meaning, the understanding of the good is understanding what is desirable.
There is a different way to think about it which is that the work could in principle be better structured to automatically be associated with more pleasure.
Aquinas addresses the virtue of perseverance and the vices opposed to perseverance in Q.137[0] and Q.138[1] of the Summa, respectively. A virtue here is "a habit that directs us to do something well, or to omit something". Perseverance allows us to avoid forsaking "a good on account of long endurance of difficulties and toils".
As a virtue, it holds the mean between the errors that flank it on either side, avoiding effeminacy and delicacy on the one hand, and pertinacity on the other.
Effeminacy "withdraws from good on account of sorrow caused by lack of pleasure, yielding as it were to a weak motion", while delicacy "is a kind of effeminacy", but while effeminacy "regards lack of pleasures [...] delicacy regards the cause that hinders pleasure, for instance toil". In other words, effeminacy shrinks from things, because of the lack of pleasure, while delicacy shrinks on account of the discomfort caused.
Pertinacity holds on "impudently, as being utterly tenacious". It resists course correction.
[0] https://aquinas.cc/la/en/~ST.II-II.Q137
[1] https://aquinas.cc/la/en/~ST.II-II.Q138