V. Nor were they less ingenious in calling the state of the soul devoid of the light of the mind, “a being out of one's mind,”“a being beside oneself.” From Project GutenbergDefinitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary...
beside oneself,almost out of one's senses from a strong emotion, as from joy, delight, anger, fear, or grief: He was beside himself with rage when the train left without him. Advertisement add this widget to your site Did You Know?
Beside myself or besides myself? The correct idiom isbeside myself(also beside yourself, beside him/herself, etc.). It means that you are in an extreme state of emotion, which is usually specified by saying ‘beside oneself with …’: She was beside herself with excitement after passing h...