Indirect Realism Flashcards
(12 cards)
What is indirect realism
Indirect realism is a theory of perception that states we perceive physical objects, which are dependent of the mind, through sense data which are caused by and represent real physical objects. Therefore the immediate object of perception is sense data.
Locke’s distinction between primary and secondary qualities
- A Primary quality (such as extension, size, and shape) are those that are inseparable from the physical object no matter how much change it goes through such as being divided into smaller pieces.
- A Secondary quality is the power that physical objects have to produce certain sensations within us, including color, smell, and taste.
- while our perceptions of primary qualities are a precise representation of the physical object and are independent of a perceiving mind, Locke says that primary qualities simply produce a feeling of e.g., greeness in my mind but this doesn’t exist in the physical object.
- secondary qualites are sense data caused by primary qualites
Supporting Locke’s Primary/Secondary quality distinction: Primary Qualities are essential
Lock arengues that Primary Qualities are those that are inseparable from the physical object. No matter how the object is altered, it must always maintain its primary properties such as size, shape, and extension. In contrast, secondary qualities do vanish (e.g, colours vanish in different lighting). So Locke concludes that secondary properties require a mind and are dependent on primary qualities.
Locke illustraits this with a grain of wheat. when we divide it, its primary qualities will remain even until we cannot see the grain. therefore, Primary qualities are independent on the mind while secondary qualities need a mind to perceive them
the Issue of scepticism about the existence of mind-independent objects
Locke suggests that our secondary qualities that we perceive do not resemble the physical objects that cause them. Yet there is nothing stopping this view to be also applied to Primary Qualities.
Therefore it can be suggested that our sense data creates a ‘veil of perception’ between us and the physical world. our only way of knowing if our sense data is representing the physical world accurately is to have a direct relation to it (which the indirect realist says we don’t).
The issue created here is that it seems if indirect realism is true, then we know nothing about the real world and therefore fall into scepticism. It is possible that we are simply brains in a vat stimulated by an evil scientists to have a perception of a physical world. Therefore it seems like if direct realism is true, we cannot know anything about the material world or even if there is one.
Issue of ideas cannot be like material objects
Berkleys argument depends on the likeliness principle, the idea that A can only resemble B if A is like B. Berkley builds on this by stating Ideas are too different and there not like physcial objects. And therefore our sense data, which indirect realism says resembles the physcial world, cannot resemble the physical world.
1) my idea of for example a tree has sensible qualities (greenness, tree shaped)
2) but these sensible qualities depend on the mind
3) to say that my idea of a tree resembles a tree is to say something invisible resembles something visible, or something without sound resembles something with sound
4) also ideas are fleeting and changing while material objects permanent and unchanging
5) thus anything outside the mind (like matter) cannot have such qualities
6) it follows that material objects cannot be like or resemble my idea of it
He argues that we cannot have knowledge of the external world from sense data, but moreover, indirect realism fails to give a satisfactory account of how sense data, the immediate objects of our perception, can resemble something so different from it.
Response to the issue of scepticism: The involuntary nature of our experiences (Locke)
Locke points out that we are not in control of our sense data. when I open my eyes I will receive certain sense data and that is not something I have any choice about. For instance, an imagination of pain while possible doesn’t inflict any pain on the subject, however, the involuntary experience of being burned does.. Because perception is not subject to my will, Locke concludes that it cannot come from yourself. And if it cannot come from myself then it must come from an external world. For, if our ideas did arise from us, an imagination of pain must be just as painful as the real thing. Therefore, even though we are not directly aware to the material world due to the veil of perception, we can be confident that there is one, therefore bypassing the issue of scepticism.
Response to the issue of scepticism: The coherence of various kinds of experiences (Locke and Cockburn)
Locke points out that many of our senses are coherent with one another and this strongly suggests that there is a physcial object causing these sense perceptions. For instance we can both see and feel the edges of the cube which result us in beleiving that the cube is sharp. It would be a big coincidence if both touch and sight confirmed the existence of such a geomtric property but for the actual cube to be non existant or have different properties.
Similarly Cockburn adds on that our ability to assosciate what an object is just by touch, and our ability to know how something feels just by looking at it, suggests that our ideas are related to material objects in reality. For instance, i can feel what is in my pocket and predict that it is my keys and pull them out and them indeed by my keys. If there was no external world that is causing my perception then it would be an extraordinary coincidence that my mental prediction based on touch would align so perfectly with the visual confirmation afterward.
This consistency between different senses strongly indicates that there is a stable, external world that exists independently of our minds and is the source of our perceptions.
Response to the issue of scepticism: The external world is the best hypothesis (Russel)
Russel agrees that there may not be any conclusive proof of an external world, but that it is still reasonable to believe in mind independent objects and the existence of a material world as it explains why things appear to us in regular and predictable ways. we can take the example of an apple: if we leave it in a closed drawer and forget it about it for a week, we will come back and find a rotten apple. The reason for this seems to be that the apple is a material object which continues to exist when not perceived and slowly rots during this time. If there is no material world at all, this would all become a very mysterious phenomenon. Russel recognises that there are other possible explanations such as an evil demon causing such a perception but states that without positive evidence of supporting these alternatives, it is the best decision to stick with the theory which does - that there truly is an external world with material objects.
What is sense data
Mental images or representations of what is perceived, the ‘content’ of perceptual experience. If sense-data exist, they are the immediate objects of perception and are ‘private’, mind-dependent mental things.
what is a primary quality
a primary quality are properties that are completely inseparable from a physical object even through whatever changes it goes through (e.g, being divided into increasingly smaller peices). Some examples are, shape, extension, and size
what is a secondary quality
Properties that physical objects have that are ‘nothing but powers to produce various sensations in us’. Locke lists ‘colours, sounds, tastes
what is solipsism
The view that only yourself, one’s mind, exists. There no mind-independent physical objects and there are no other minds either.
