Outward objects intrude
These occasions of wandering thoughts lie within, are wrought into our very nature. But they will likewise naturally and necessarily arise from the various impulse of outward objects. Whatever strikes upon the organ of sense, the eye or ear, will raise a perception in the mind. And accordingly, whatever we see or hear will break in upon our former train of thought. Every man therefore who does anything in our sight, or speaks anything in our hearing, occasions our mind to wander more or less from the point it was thinking of before.
1771 text
8. *These occasions of wandering thoughts lie within, are wrought into our very nature. But they will likewise naturally and necessarily arise, from the various impulse of outward objects. Whatever strikes upon the organ of sense, the eye or ear, will raise a perception in the mind. And accordingly, whatever we see or hear, will break in upon our former train of thought. Every man therefore that does any thing in our sight, or speaks any thing in our hearing, occasions our mind to wander more or less from the point it was thinking of before.