3p12d.md (770B)
1 So long as the human body is affected in a mode, which 2 involves the nature of any external body, the human mind will 3 regard that external body as present (II. xvii.), and 4 consequently (II. vii.), so long as the human mind regards an 5 external body as present, that is (II. xvii. note), conceives it, 6 the human body is affected in a mode, which involves the nature 7 of the said external body; thus so long as the mind conceives 8 things, which increase or help the power of activity in our body, 9 the body is affected in modes which increase or help its power of 10 activity (III. Post. i.); consequently (III. xi.) the mind's 11 power of thinking is for that period increased or helped. Thus 12 (III. vi., ix.) the mind, as far as it can, endeavours to imagine 13 such things. Q.E.D. 14 15