Sense perception is the use of our senses to acquire information about the world around us and to become acquainted with objects, events, and their features. Traditionally, there are taken to be five senses: sight, touch, hearing, smell and taste.
Philosophical debate about perception is ancient. Much debate focuses on the contrast between appearance and reality. We can misperceive objects and be misled about their nature, as well as perceive them to be the way that they are: you could misperceive the shape of the page before you, for example. Also, on occasion, it may seem to us as if we are perceiving, when we do not perceive at all, but only suffer hallucinations.
Illusions and hallucinations present problems for a theory of knowledge: if our senses can mislead us, how are we to know that things are as they appear, unless we already know that our senses are presenting things as they are? But the concern in the study of perception is primarily to explain how we can both perceive and misperceive how things are in the world around us. Some philosophers have answered this by supposing that our perception of material objects is mediated by an awareness of mind-dependent entities or qualities: typically called sense-data, ideas or impressions. These intermediaries allegedly act as surrogates or representatives for external objects: when they represent aright, we perceive; when they mislead, we misperceive.
An alternative is to suppose that perceiving is analogous to belief or judgment: just as judgment or belief can be true or false, so states of being appeared to may be correct or incorrect. This approach seeks to avoid intermediary objects between the perceiver and the external objects of perception, while still taking proper account of the possibility of illusion and hallucination. Both responses contrast with that of philosophers who deny that illusions and hallucinations have anything to tell us about the nature of perceiving proper, and hold to a form of naïve, or direct, realism.
The account of perception one favours has a bearing on one’s views of other aspects of the mind and world: the nature and existence of secondary qualities, such as colours and tastes; the possibility of giving an account of the mind as part of a purely physical, natural world; how one should answer scepticism concerning our knowledge of the external world.
The theory of επινοια in st. Basil of Caesarea and Eunomius of Cyzicus: philosophical and theological background
