Hermann von Helmholtz: Quotes about reason

Hermann von Helmholtz was physicist and physiologist. Explore interesting quotes on sense.
Hermann von Helmholtz: 24   quotes 1   like

“As you are aware, no perceptions obtained by the senses are merely sensations impressed on our nervous systems.”

"On the Physiological Causes of Harmony" (1857), p. 81
Popular Lectures on Scientific Subjects (1881)
Context: As you are aware, no perceptions obtained by the senses are merely sensations impressed on our nervous systems. A peculiar intellectual activity is required to pass from a nervous sensation to the conception of an external object, which the sensation has aroused. The sensations of our nerves of sense are mere symbols indicating certain external objects, and it is usually only after considerable practice that we acquire the power of drawing correct conclusions from our sensations respecting the corresponding objects.

“The sensations of our nerves of sense are mere symbols indicating certain external objects, and it is usually only after considerable practice that we acquire the power of drawing correct conclusions from our sensations respecting the corresponding objects.”

"On the Physiological Causes of Harmony" (1857), p. 81
Popular Lectures on Scientific Subjects (1881)
Context: As you are aware, no perceptions obtained by the senses are merely sensations impressed on our nervous systems. A peculiar intellectual activity is required to pass from a nervous sensation to the conception of an external object, which the sensation has aroused. The sensations of our nerves of sense are mere symbols indicating certain external objects, and it is usually only after considerable practice that we acquire the power of drawing correct conclusions from our sensations respecting the corresponding objects.

“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.”

"On the Physiological Causes of Harmony" (1857), p. 81
Popular Lectures on Scientific Subjects (1881)
Context: 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.