This is a question which interests me a lot, and is central in my literature as well 
The sensation of fear, and horror, is obviously ancient, but one should guess that it predated its first manifestation in humans or their ancestors. That for the simple reason that did that which enable it form not predate its first cause, then the cause itself could not have shaped it in any way. This irregardless of the logical argument that despite such a claim that first cause would have had an impact, and so would the next causes.
Fear seems to be at least categorisable into two main types, in relation to our own consciousness of what had caused it. The first is fear caused by an external object, for example from a pack of wolves. The second is fear caused either in the absense of such an external cause, or by a psychotic episode. For example one can feel horror by closing his eyes and imagining against his will some hideous form, and then being alarmed that this had happened.
Ofcourse the fear caused by an external object is again synthesised with the fear caused by a non-external object, due to the fact that even an external object remains to be a mental object, viewed as different from an imaginary one for reasons of how our consciousness has developed in time. However if one is in a mountain resort, walking outside it in the snow, and there sees a wolf, he will not be wondering if the wolf is understood by him as a mental image or not, but be clearly worried about the wolve's teeth which could possibly bite into him if he is not carefull. In essense, perhaps, fear of an external object is not entirely different from fear of an internal one, but here the difference that the internal one has appeared for unexplained reasons (unlike the appearence of the wolf, which was caused by its own nature and psysical form) provides another parameter in the threatening emotion.
'Fear of the unknown' is a common phrase, although ofcourse one should agree that it has been used to refer to cases of largely different essense. But fear of the unknown can be expected to hit a very sensitive note inside one's mind, namely that whose meaning is that we cannot realise where we are moving inside our consciousness. Symbolically one could say that a person who suffers from a short episode of such horror caused by an internal object is in a way stumbling inside a corridor in his mind, or rather has fallen inside a small pit, whereas before he had been walking in fast pace without being aware of the existence of such mental pits.
Very important is to note that there are many other factors of horror caused by internal objects, which do not expand possibly all the way towards the deeper question about the ability we have to feel fear. For example in early childhood it is ussual that small children identify physical form with characteristics of character, and therefore they can personify a negative- or a positive- characteristic in one's actual body. Due to this a child can see his mother as a demon, or as an angelic being. However this fact of psychology does not explain how and why one is able to demonise.
It seems very likely- if not absolutely certain- that the ability to demonise, or to angelify, is linked with the ability to form scales of appreciation of the form and of any other characteristic. Everyone has these scales, and they serve as a background (they can also be in the foreground of thought ofcourse, as is very ussual in adolescence) in one's decisions about what is to him good and what is not.
In the genealogy of ethics, Nietzsche had claimed that the origins of the notions of good and evil appear to have strong connections with the notions of beautiful and ugly. Following some developments of this thought he reached the conclusion that ethics have been serving either as a tool of the noble/strong against the weak, or in more decadent times which he saw in christianity, as a tool of the weak against the strong. However he did not try to examine the origin of the scales of comparisson which inevitably are to be found beneath the notions of beautiful and ugly, or of good and evil.
My view is that horror, as an emotion, deserves very serious research, and ofcourse in the world of art it has a place as well. Ideally in the future we will have very different terms for all emotions, mental mechanisms, thought patterns and overall moods, and those should be heavily de-socialised and de-humanised, but be more particular to the state of the ego inside the world of personal consciousness.
With my own literature i have the goal of discussing this issue, and also utilising universal symbolisms so as to provoke the bridges which are lowered above the dark river which normally seperates us from horror, to present theirselves more clearly. Definately horror is personal to anyone, but like any other topic, it too can be examined from a more overall perspective as well

The sensation of fear, and horror, is obviously ancient, but one should guess that it predated its first manifestation in humans or their ancestors. That for the simple reason that did that which enable it form not predate its first cause, then the cause itself could not have shaped it in any way. This irregardless of the logical argument that despite such a claim that first cause would have had an impact, and so would the next causes.
Fear seems to be at least categorisable into two main types, in relation to our own consciousness of what had caused it. The first is fear caused by an external object, for example from a pack of wolves. The second is fear caused either in the absense of such an external cause, or by a psychotic episode. For example one can feel horror by closing his eyes and imagining against his will some hideous form, and then being alarmed that this had happened.
Ofcourse the fear caused by an external object is again synthesised with the fear caused by a non-external object, due to the fact that even an external object remains to be a mental object, viewed as different from an imaginary one for reasons of how our consciousness has developed in time. However if one is in a mountain resort, walking outside it in the snow, and there sees a wolf, he will not be wondering if the wolf is understood by him as a mental image or not, but be clearly worried about the wolve's teeth which could possibly bite into him if he is not carefull. In essense, perhaps, fear of an external object is not entirely different from fear of an internal one, but here the difference that the internal one has appeared for unexplained reasons (unlike the appearence of the wolf, which was caused by its own nature and psysical form) provides another parameter in the threatening emotion.
'Fear of the unknown' is a common phrase, although ofcourse one should agree that it has been used to refer to cases of largely different essense. But fear of the unknown can be expected to hit a very sensitive note inside one's mind, namely that whose meaning is that we cannot realise where we are moving inside our consciousness. Symbolically one could say that a person who suffers from a short episode of such horror caused by an internal object is in a way stumbling inside a corridor in his mind, or rather has fallen inside a small pit, whereas before he had been walking in fast pace without being aware of the existence of such mental pits.
Very important is to note that there are many other factors of horror caused by internal objects, which do not expand possibly all the way towards the deeper question about the ability we have to feel fear. For example in early childhood it is ussual that small children identify physical form with characteristics of character, and therefore they can personify a negative- or a positive- characteristic in one's actual body. Due to this a child can see his mother as a demon, or as an angelic being. However this fact of psychology does not explain how and why one is able to demonise.
It seems very likely- if not absolutely certain- that the ability to demonise, or to angelify, is linked with the ability to form scales of appreciation of the form and of any other characteristic. Everyone has these scales, and they serve as a background (they can also be in the foreground of thought ofcourse, as is very ussual in adolescence) in one's decisions about what is to him good and what is not.
In the genealogy of ethics, Nietzsche had claimed that the origins of the notions of good and evil appear to have strong connections with the notions of beautiful and ugly. Following some developments of this thought he reached the conclusion that ethics have been serving either as a tool of the noble/strong against the weak, or in more decadent times which he saw in christianity, as a tool of the weak against the strong. However he did not try to examine the origin of the scales of comparisson which inevitably are to be found beneath the notions of beautiful and ugly, or of good and evil.
My view is that horror, as an emotion, deserves very serious research, and ofcourse in the world of art it has a place as well. Ideally in the future we will have very different terms for all emotions, mental mechanisms, thought patterns and overall moods, and those should be heavily de-socialised and de-humanised, but be more particular to the state of the ego inside the world of personal consciousness.
With my own literature i have the goal of discussing this issue, and also utilising universal symbolisms so as to provoke the bridges which are lowered above the dark river which normally seperates us from horror, to present theirselves more clearly. Definately horror is personal to anyone, but like any other topic, it too can be examined from a more overall perspective as well

