For passion is the effect of action; and in nature contraries are mutually active or passive, according as one thing changes another from its natural disposition.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic action passion
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

“"Excessive suffering wastes the very substance." I answer that, "Passion" may be taken in two senses. First, in its proper sense, and thus a thing is said to suffer when changed from its natural disposition. For passion is the effect of action; and in nature contraries are mutually active or passive, according as one thing changes another from its natural disposition. Secondly, "passion" can be taken in a general sense for any kind of change, even if belonging to the perfecting process of nature. Thus understanding and sensation are said to be passions. In this second sense, man was passible in the state of innocence, and was passive both in soul and body.” source