Nothing is an object unless there is a subject to consider it. While not questioning the existence of objects when not directly considered, in “The World as Idea”, Arthur Schopenhauer (1788-1860) says that we only know the world in relation to ourselves, to the extent that we are conscious of it. There is no independent verification of the fact that things, objects in the world, the world itself -are in fact what we perceive them to be.
This introduces an important distinction into the discussion, namely, (a) the object, and (b) the knowledge we have of it based on our perception of it. We can make this distinction on the basis that, if we have knowledge of an object, it presupposes the existence of it, and that its existence is a function of the way it exists in the world through its various attributes, e.g., attributes related to its spatial dimensions, shape, color, etc., and that it has these attributes regardless of anyone being able to perceive them or not.
Consider that our perception of objects is, in the first instance, a function of two things. Firstly, an object being the causal element in the act of perceiving it, and secondly, the ability of our perceptual apparatus to process the sensory information in a manner that is assumed to be reliable in being able to reproduce the object accurately as a discernible event in one’s stream of consciousness. The latter would form the basis on which variable degrees of knowledge of the object can be formulated, depending on the quality and nature of the experience, and whatever else might have been know about the object prior to the particular perception of it at a given moment in time.
The latter is relevant as there are going to be differences between perceived objects on the basis that we may already have beliefs about them. In short, people sometimes see what they want to see, or are expecting to see. On this topic Nietzsche said in 1887:
As soon as we see a new image, we immediately construct it with the aid of all our previous experiences, depending on the degree of our honesty and justice. All experiences are moral experiences, even in the realm of sense perception.
This is a whole topic on its own, and we won’t go there just now, but it is just another reminder that our perception of objects might be suspect when it comes to their accuracy. But for the current exercise we’ll proceed on the premise that sensory perception is by and large a reliable enterprise, and see where it will get us.
Having said that, there is in fact some manipulation going on by the time the object arrives in our stream of consciousness as a perceptual event. Before it arrives there, it will have been processed by our brain’s neural network on the basis of the nature of the data received from the sensory organs (eyes, ears, etc.) and – as I inferred earlier – we give this process the benefit of the doubt in being able to reproduce the object exactly as it was presented to us at the moment of perception. As much as the act of perceiving is entirely transparent to the perceiver such that it would appear we have direct access to the object, I’m merely stating this as a reminder that, in fact, we do not, as we are always one step removed from it.
Finally, in addition to there being a neurological process to convert objects being perceived into mental objects in one’s stream of consciousness, human beings – as all other creatures that live on earth – will have had their sensory organs evolved to the degree that this was necessary for them to survive as a species. As such we can point to significant differences between species in how objects are perceived in terms of their properties. Think about the highly developed sense of smell that a dog has versus what the average human nose is able to detect. When faced with the same object, this would produce a different object for the perceiver with respect to at least one of its properties. To a lesser degree there are going to be (however subtle) differences between the perceived version of the same objects between humans on the basis of their individual physiologies.
So the question for us here is: Regardless of the degree of knowledge we have of an object – e.g., we only know some of its properties, do we have any reason to believe that objects in the world are in fact not what we perceive them to be? What else could they be other than what we perceive them to be? Does anyone care? Why do philosophers worry about this? Philosophers such as Immanuel Kant (1724-1804) introduce such concepts as the “thing-in-itself” (“ding ansich”) to suggest that the true nature of things in the world is fundamentally unknowable as we can only grasp the nature of things indirectly through perceiving them as objects in relation to ourselves – how we have experienced them. As I attempted to point out earlier, our knowledge of the world is – so to speak – tainted by human perception, i.e., as Nietzsche says, there is no immaculate perception.
Let it suffice that (a) objects exist regardless of anyone having any knowledge of them, and (b) if we do have knowledge of an object, it would be reasonable to assume that it exist as perceived, but that (c) we will never know that it exist exactly in the manner in which we believe its exists – as that level of knowledge is simply not available to us as it cannot be verified outside the act of perception.
This leads me to conclude that – while we can make the distinction I made earlier – between (a) an object, and (b) the knowledge we have of that object, it is in fact a logical distinction as well as an ontological distinction, and that to all intents and purposes the knowledge we have of an object is in fact knowledge of its mental replica we carry around in our stream of consciousness , and that – as such – the subject defines the object to the extent that this is the only way an object is available to the subject.
So now I would be tempted to say that, whatever knowledge we have of the physical world and derived through the senses (is there any other way?), this knowledge may not be entirely truthful with respect to what it is telling you about the world and everything in it. This is what French Philosopher Rene Descartes (1596-1650) concluded about the reliability of sensory experiences:
Whatever I have accepted until now as most true has come to me through my senses. But occasionally I have found that they have deceived me, and it is unwise to trust completely those who have deceived us even once.
Now “deceived” is a strong word – implying an intentionally malicious act – and I would have preferred to say that discrepancies might occur between (a) the object being perceived and (b) our perceptual apparatus being able to reproduce it accurately as a mental object in the stream of consciousness. Such is the nature of reality.
(I’m leaving some other problems alone here, e.g., in philosophy 101 we should have all learned that you cannot deduce a cause from an effect – that to do so is a logical fallacy. In the movie The Matrix they made that work by placing hapless human minds at the receiving end of a causal chain that made them interact with objects in a virtual reality that was entirely software generated. So, again, even if you have a mental construct of an object in your consciousness, there is no guarantee that it does in fact exist in the world in the manner that you believe it to be, and you may only have been led to believe that it was there.)