אִם־אַ֭תָּ֗ה הֲכִינ֣וֹתָ לִבֶּ֑ךָ וּפָרַשְׂתָּ֖ אֵלָ֣יו כַּפֶּֽךָ׃
Malbim on Job
Regardless of the philosophical and theological problems, subjectively, man knows that he has free-will. He feels no inherent restrictions on his choices. Whatever the mind decides, the body effects.