Tackling Catholic philosophy and theology I'd like to read and understand Catholic theology, philosophy and Tradition as best as I can. 

I'm a biologist and not a philosopher/theologian -- and as such, I cannot (and thus far have not) dedicated massive amounts of time to reading/understanding explicitly the texts and concepts of specific philosophers/theologians in their entirety. I'm not opposed to reading the many influential authors, but given my lack of time to dedicate fully to this endeavor, I'd like to go about reading these authors in the most efficient way, if you will. 

My question then: which major texts/authors should I prioritize reading (and in what order) to better grasp the current theology/philosophy of the Catholic faith?

My impression is, that I would benefit greatly reading the following (with supposed additions added in parentheses) in the presented order (first to last):

(Plato) &gt; Aristotle &gt; Irenaeus &gt; Augustine &gt; Aquinas &gt; Ratzinger 


Does this seem sensible? Are each of these authors necessary (as I suppose) to truly understand the other? Or can I read Aquinas or Ratzinger (for example) and get a good enough grasp of prior thought/philosophers? Are there other authors that are hugely important that I skipped (e.g., Descartes?)?

Is there a textbook perhaps that anyone can recommend that introduces me to a sensible and necessary reading list or conceptual walkthrough? 

(I guess I'm ultimately looking for an "official" list (perhaps from a well-respected textbook, theologian, or the Church itself) vs anecdotal commentary. )
Read St. Thomas Aquinas, especially his Summa Theologica or his own briefer introductory summary of it, the Compendium Theologiæ.
From Fr. Réginald Garrigou-Lagrange, O.P.'s Essence &amp; Topicality of Thomism pt. 1, §2 &quot;The Excellence of Thomism&quot;:

St. Robert Bellarmine similarly speaks of St. Thomas in the introduction of his treatise on the Holy Trinity:

Certainly, if everyone proposes with such order, facility, and brevity to us, as I venture to affirm, that he who diligently studies a few of St. Thomas’s questions finds nothing difficult either in Scriptures, the Councils, or the future Fathers of the Trinity; he will make more all-around progress in two months devoted to the Summa than in several months’ study of the Scriptures and the Fathers.

Pope John XXII also said:

He (St. Thomas) has illuminated the Church more than all the other Doctors; to read his books for a year profits man more than to study the doctrine of others for his whole life.


All good, orthodox, Catholic theology is merely footnotes to the Angelic Doctor. Every pope since the 13th century has endorsed his work as thoroughly Catholic; see the magisterial endorsements quoted here. His Summa Theologica was even placed on the altar, alongside Holy Scriptures, as an authority at the Council of Trent!