352. Those who have deliberately avoided thinking of the Divine when observing the marvels in nature, and who thereby become sensual, do not reflect that the sight of the eye is so gross that it sees many little insects just as if they were one obscure insect, when yet every single one of them is furnished with organs of feeling and motion, and thus is possessed of fibres and vessels, a tiny heart also, and lung tubes, minute viscera and brains; and that these organs are woven out of the purest substances in nature, their tissues corresponding to something of life, by which their minutest parts are separately moved. Since the sight of the eye is so gross that many such little insects, with innumerable parts to each one, appear to it as an obscure speck, and yet, by that sight. those who are sensual think and judge, it is plain how their minds have been dulled, and into what darkness it has brought them concerning spiritual things.