St. Thomas is full of wisdom for everyone, from his times to contemporary times. I'm not sure my intellect or time management will ever allow me to read the Summa Theologica in completion, but I have been working on "A Shorter Summa: The Essential Philosophical Passages of St. Thomas Aquinas Summa Theologica Edited and Explained" by Peter Kreeft with my Dominican group. It is a book and edition I would recommend.
It's always reassuring that in the presence of very smart people, including lawyers and those who have had advanced theological training, they also have a hard time wrapping their mind around deep philosophy and pulling from their recesses of their mind writings by Aristotle, Plato and other early philosophers.
Thinking deeply really makes me feel my age. I may have studied philosophy 15 years ago, and it may have been easier then, perhaps my brain cells were fresher (or it may have been because I drank more wine and margaritas back then). Though reading St. Thomas' writing stretches my ability, it is worthwhile.
I will share a little of what I have read in St. Thomas Aquinas' Question 2 in Ethics VII, in which he discusses "Of Those Things in Which Man's Happiness Consists".
He has his writings set up in a statement/ counter statement format.
1) Whether Man's Happiness Consists in Wealth
2) Whether Man's Happiness Consists in Honors
3) Whether Man's Happiness Consists in Fame or Glory
In our Donald Trump/ Kim Kardashian society, it is interesting to read his points and counterpoints in which he lays out that Man's happiness consists in living a true and virtuous life.
1) Whether Man's Happiness Consists in Wealth- he goes through several objections and counter statements of how this is not the case; one of his final arguments though is from Boethius. ii. wealth shines in giving rather than hoarding: for the miser is hateful, whereas the generous man is applauded" which Kreeft cited as, "Money, unlike happiness, is good only when spent, not kept."
2) Whether Man's Happiness Consists in Honors- "virtue's true reward is happiness itself, for which the virtuous work: whereas if they worked for honor, it would no longer be a virtue, but ambition". Some of his writings on this point made me extrapolate to our modern day world and social media. Whether it be Facebook or Pinterest, in social media some people work hard to show what a wonderful life they have. Sometimes presenting how happy you are to everyone else leaves little time to enjoy your life, as Kreeft says, "Going on vacation just to take pictures of it."
3) Whether Man's Happiness Consists in Fame or Glory- "human glory is frequently deceptive" and "fame has no stability; in fact it is easily ruined by false report". Our group then went on to point out examples of people who didn't get credit for their work, or people who work all their lives to build a reputation only to lose it, " Joe Paterno was cited as an example of someone who had a flawless reputation... until he didn't...
The above is just a tidbit from St. Thomas Aquinas' writing, which though, deep and intellectually challenging when read, could have just as easily been written today as it was long ago. Hopefully, the above has piqued your interest to explore him more. I do recommend Peter Kreeft's book "A Shorter Summa", as mentioned above, as being maybe a little more accessible to the average person.