Unless there is something to prevent it, a motion or operation follows the appetite.
Thus, if the judgment of the cognitive faculty is not in a person's power but is determined for him extrinsically, neither will his appetite be in his power: and consequently neither will his motion or operation be in his power absolutely.
Now judgment is in the power of the one judging in so far as he can judge about his own judgment; for we can pass judgment upon the things which are in our power. But to judge about one's own judgment belongs only to reason, which reflects upon its own act and knows the relationships of the things about which it judges and of those by which it judges.
Hence the whole root of freedom is located in reason. Consequently, a being is related to free choice in the same way as it is related to reason.
--Saint Thomas Aquinas, Truth, Question 24: Article 2, Reply.*
Cf. Then Jesus said to those Jews, who believed him: If you continue in my word, you shall be my discipl es indeed. And you shall know the truth, and the truth shall make you free. John 8:31-32
N.B. "Who am I to judge?" --Pope Francis, RIP! Answer: you are a man endowed with reason, and your power of judgment is what makes you a man, a man fit for human life, a man fit for heaven, a man endowed with the power of Wisdom Himself, to know and to love and to know the difference between knowing and not knowing, between love and its contraries!
Cf. The Homo-Heresy in the Church: Viganò Complete Interview
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*The translation of the text above is taken from Saint Thomas Aquinas, Truth, trans. Robert Schmidt, SJ, Chicago: Henry Regnery Company, 1954, vol. III, p. 146. I was referred to this quote by Pieper, Sentenzen über Gott und die Welt: Latein.-Dtsch, #152.