When the will of the person choosing is incited to make a choice by the good already pre-existing in the object chosen, the choice must needs be of those things which already exist, as happens in our choice.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic choice good
Date 1274
Language English
Reference
Note Translated by Fathers of the English Dominican Province
Weblink http://www.gutenberg.org/cache/epub/17611/pg17611-images.html

Context

“But if we consider the communication of this or that particular good, He does not allot it without election; since He gives certain goods to some men, which He does not give to others. Thus in the conferring of grace and glory election is implied. Reply Obj. 2: When the will of the person choosing is incited to make a choice by the good already pre-existing in the object chosen, the choice must needs be of those things which already exist, as happens in our choice. In God it is otherwise; as was said above (Q. 20, A. 2) . Thus, as Augustine says (De Verb. Ap. Serm. 11) : "Those are chosen by God, who do not exist; yet He does not err in His choice." Reply Obj.” source