Thirdly, the bondings arising from vision
The spirit is also bonded through vision, as has been said frequently above, when various forms are observed by the eyes. As a result, active and passive items of interest pass out from the eyes and enter into the eyes. As the adage says, ‘I do not know whose eyes make lambs tender for me’.
Beautiful sights arouse feelings of love, and contrary sights bring feelings of disgrace and hate. And the emotions of the soul and spirit bring something additional to the body itself, which exists under the control of the soul and the direction of the spirit. There are also other types of feelings which come through the eyes and immediately affect the body for some reason: sad expressions in other people make us sad and compassionate and sorry for obvious reasons.
There are also worse impressions which enter the soul and the body, but it is not evident how this happens and we are unable to judge the issue. Nevertheless, they act very powerfully through various things which are in us, that is, through a multitude of spirits and souls. Although one soul lives in the whole body, and all the body’s members are controlled by one soul, still the whole body and the whole soul and the parts of the universe are vivified by a certain total spirit.
Hence, the explanation of many spiritual feelings must be found in something else which lives and is conscious in us, and which is affected and disturbed by things which do not affect or disturb us.
And sometimes we are touched and injured more significantly by those things whose assaults we are not aware of than we are by things which we do perceive. As a result, many things which are seen, and forms which are absorbed through the eyes, do not arouse any consciousness in our direct and external sensory powers. Nevertheless, they do penetrate more deeply and lethally, so that the internal spirit is immediately conscious of them, as if it were a foreign sense or living thing. Thus, it would not be easy to refute some of the Platonists and all of the Pythagoreans, who believe that one human person of himself lives in many animals, and when one of these animals dies, even the most important one, the others survive for a long time.
Hence, it would obviously be stupid to think that we are affected and injured only by those visible forms which generate clear awareness in the senses and the soul. That would not be much different from someone who thinks that he is injured more or less only by blows of which he is more or less conscious. However, we experience more discomfort and suffering by being pricked by a needle or by a thorn irritating the skin than we do by a sword thrust through from one side of the body to the other, whose effect is later felt a great deal more, but at the time we are unaware of the injury caused by its penetration of parts of the body.
So, indeed, there are many things which stealthily pass through the eyes and capture and continuously intrude upon the spirit up to the point of the death of the soul, even though they do not cause as much awareness as do less significant things. For example, seeing certain gestures or emotions or actions can move us to tears. And the souls of some faint at the sight of the spilling of another’s blood or in observing the dissection of a cadaver. There is no other cause of this than a feeling which binds through vision.
Giordano Bruono, Cause, Principle and Unity, And Essays on Magic. p. 137-138