A fundamental basis of Empiricism is the formation of concepts based on sense impressions. Empiricism claims that all of our concepts are formed out of sense experiences. The majority of what we are conscious of is what we are actually sensing. For example I would be aware if I were drinking coffee as I would actually be smelling, tasting and seeing it. But I can think about coffee when it is not present, thus I have formed its concept. So if I was to encounter it again, I could recognise it but more importantly I am able to hold a belief about it – such as it helps me to stay awake. We also have inner impressions such as discomfort or happiness. It is the combination of these impressions that Empiricists claim we can form any concept, even one we have not perceived. For example, we are able to imagine mystical creatures such as dragons even though we have never seen one. I am able to imagine a fire breathing dragon with horns and spikes on its back. I do this by taking the horns from a bull, the spikes from a reptile and the fire from a bonfire to compose my imaginary dragon.
David Hume strengthened this Empiricist view by distinguishing between simple and complex concepts – or what he called ‘ideas’. Simple ideas consist of a single element, such as the idea of red while complex ideas involve multiple simple ideas, such as a gold medal. All simple ideas must derive from simple impressions. For example my idea of red must have come from my sense impression of red. Hume claimed that we have inward and outward impressions. In other words, not all impressions are sense impressions whereby emotions count as impressions too. This means that not all of our ideas come from sense experience as some ideas such as sadness will be derived from inward impressions.
On the other hand, does the concept of ‘simple ideas’ really make sense? Are the ‘simple’ ideas put forth by Empiricists really that simple? Locke and Hume gave examples such as red, cold and sadness as examples of simple impressions and claimed they could not be broken down or analysed into anything simpler. But how precisely are complex ideas, such as a unicorn, analysed into simple ones? If we analyse a unicorn with the Empiricist view we get a horse and a horn. But it seems that these ‘simple concepts’ could be analysed further. We could begin to describe the horn as pointy or sharp and the horse with a mane, hooves and nostrils. Perhaps we could go further and define the mane as a complex idea – with regards to the bundle of hair, and then even analyse the hair further. So to what extent do we need to analyse a concept to classify it as simple? Furthermore if we take the ‘simple’ concept of a horse neighing we hear multiple sounds. And the sense impression which gives us the concept of the horse neighing is complete in itself, but if we were to break it down into the single sounds we would lose the essence of the concept. This begins to show difficulties Empiricists have when working out details of their theories about what counts as a simple impressions.
A further criticism of sense experience is Hume’s Missing Shade of Blue. The MSB shows us a range of the colour blue, from which one is missing, and asks someone whether they can work out the missing shade. If Empiricists were to say that you could form the concept of the missing shade – which seems plausible – it means that it is possible to form a concept which has no corresponding impression. However, this goes against the Empiricist principle that nothing can exist in the mind that hasn’t come through the senses. Hume states this to be the exception to the general rule of sense experience. But if we can form this concept without our senses, why can’t that apply to other concepts?
Another significant concept in Empiricism is Logical Positivism. Logical Positivism in its simplest form is classifying whether or not a sentence is meaningful or not. Logical Positivists argued that language was only meaningful if it confined itself to discussing what was within human experience. Once we go beyond what we can experience then we venture into nonsense. A.J Ayer was a key Logical Positivist and strongly defended the Verification Principle. The V.P is a test that a sentence must pass if it is genuinely meaningful, which states that a sentence is meaningful if it is either a tautology or it can hypothetically be proved to be true or false, i.e. it is verifiable. If a proposition isn’t a tautology and there is no way of empirically discovering its truth, then it is meaningless. The principle suggests meaningful sentences are those that say the world is either this way or that way. So if we came across a proposition that we were unsure about what it said about the world, we would class it as meaningless. However if we look towards scientific claims, such as water boils at 100 degrees Celsius, problems start to rise. How can we be sure that every drop of water in the world boils at exactly 100 degrees? It would be extremely difficult to prove, which is also the case for many other scientific claims. To deal with this problem, Ayer differentiates between a strong and weak version on verification. Strong Verification states that a statement is meaningful if we could verify it by our own observation and therefore establish its truth or falsity for certain. Whereas Weak Verification states that a statement is meaningful if there are some observations that could establish the probable truth of the statement. If we take the statement ‘there is life on the sun’ it seems that we cannot verify this. However for Ayer such a claim is meaningful as we could, in principle, take a heatproof spaceship to the sun to verify it. So Ayers modified V.P does not say we can factually verify all meaningful propositions just that we could do so in principle.
A fundamental flaw in the Verification Principle is that it does not pass the Verification ‘test’ itself. The principle claims that for any proposition to be meaningful it must be hypothetically verifiable or true by definition. This itself is a proposition about the world, so to be meaningful we must be able to imagine how we could verify its truth. However, it is hard to imagine how the world would differ if the principle was true or false thus finding it difficult to see what counts as verifying its truth. So the VP itself is meaningless according to itself.
Furthermore the Verification Principle seems far too strong as it not only makes religious language meaningless but also much of what humans speak and write about to be meaningless too, including art, poetry and inner sensations. This means it makes all ethical judgements merely a personal feeling and makes philosophical theories nonsense. Though this is not an actual problem it suggests Ayers idea of meaning to be different to the one that we use in everyday life.
In conclusion, I think that Empiricism cannot be reliable as it focuses much on the claim that we perceive the physical world only indirectly through the senses. So if we do not perceive the world directly, then what causes my sense impressions? Perhaps I am living a dream, or maybe being deceived by a super computer or an arch deceiver. What if what I perceive is not correct? Then, according to Empiricism, I ultimately have no knowledge.