Now it is a universal law of the perceptions obtained through the senses that we pay only so much attention to the sensations actually experienced as is sufficient for us to recognise external objects. In this respect we are very one-sided and inconsiderate partisans of practical utility; far more so indeed than we suspect. All sensations which have no direct reference to external objects, we are accustomed, as a matter of course, entirely to ignore, and we do not become aware of them till we make a scientific investigation of the action of the senses, or have our attention directed by illness to the phenomena of our own bodies. Thus we often find patients, when suffering under a slight inflammation of the eyes, become for the first time aware of those beads and fibres known as mouches volantes swimming about within the vitreous humour of the eye, and then they often hypochondriacally imagine all sorts of coming evils, because they fancy that these appearances are new, whereas they have generally existed all their lives.

What It Means

This is a placeholder explanation generated by the low-overhead model. It interprets "Now it is a universal law of the perceptions obtained through the senses that we pay only so much attention to the sensations actually experienced as is sufficient for us to recognise external objects. In this respect we are very one-sided and inconsiderate partisans of practical utility; far more so indeed than we suspect. All sensations which have no direct reference to external objects, we are accustomed, as a matter of course, entirely to ignore, and we do not become aware of them till we make a scientific investigation of the action of the senses, or have our attention directed by illness to the phenomena of our own bodies. Thus we often find patients, when suffering under a slight inflammation of the eyes, become for the first time aware of those beads and fibres known as mouches volantes swimming about within the vitreous humour of the eye, and then they often hypochondriacally imagine all sorts of coming evils, because they fancy that these appearances are new, whereas they have generally existed all their lives." in the context of ""On the Physiological Causes of Harmony" (1857), p. 81" to mean that wisdom is timeless.