"Alexander and Averroes laid it down that the final happiness of man is not in such knowledge as is possible to man through the speculative sciences, but in a knowledge gained by conjunction with a separately subsistent intelligence, which conjunction they conceived to be possible to man in this life. But because Aristotle saw that there was no other knowledge for man in this life than that which is through the speculative sciences, he supposed man not to gain perfect happiness, but a limited measure of happiness suited to his state. In which it sufficiently appears how hard pressed on this side and on that these fine geniuses were [(quantam angustiam patiebantur hinc inde eorum praeclara ingenia)]. From [which] stress of difficulty [(angustiis)] we shall find escape in positing, according to the proofs already given, that man can arrive at true happiness after this life, the soul of man being immortal. In this . . . state the soul [(in quo statu anima (no 'disembodied'!))] will understand in the way in which pure spirits [(substantiae separatae)] understand. The final happiness of man then will be in the knowledge of God, which the human soul has after this life according to the manner in which pure spirits [(substantiae separatae)] know Him."
St. Thomas Aquinas, Summa contra Gentiles III.48., trans. Rickaby (http://www2.nd.edu/Departments/Maritain/etext/gc3_48.htm), modifications and underscoring mine. Latin from Corpus Thomisticum here: http://www.corpusthomisticum.org/scg3001.html#25987. angustia Pesch translates as Angst ("Das Streben nach der beatitudo bei Thomas von Aquin im Kontext seiner Theologie: historische und systematische Fragen," Freiburger Zeitschrift für Philosophie und Theologie 52, no. 3 (2005): 431), but "difficulty, distress, [and] perplexity" (Andrews, A copious and critical Latin-English lexicon (1868)) would be a consequence of finding oneself, no matter how brilliant, between a rock and a hard place (angustiam . . . hinc inde) philosophically. There is no entry for angustia in Schütz's Thomas-Lexikon as reproduced here (http://www.corpusthomisticum.org/tl.html), but "difficulty, distress" are the equivalents given in the Lexicon of Saint Thomas Aquinas by Deferrari and Barry (for what little that may be worth).