The philosopher David Hume worked on epistemology (the study of knowledge), he set out to determine how knowledge is acquired and verified through reasoning. he wanted to establish whether it is possible to rationally justify past to future experience through inference. According to Hume, this is not rational. I agree with this position and will first set out Hume’s view and then explain why I agree with it.
The acquisition of knowledge will be outlined in its two forms, deductive and inductive. Then Hume’s work regarding this and his conclusion that inference from past to future is not rational will be considered. Criticism and concerns expressed by a fellow philosopher will be noted and discussed.
In order to proceed it is necessary to consider the two types of reasoning under examination, the first of which is deduction or deductive reasoning. This type of reasoning is concerned with relations of ideas, as opposed to inductive reasoning which is concerned with matters of fact. According to the glossary in the OU coursebook a definition of deduction is given as ‘Deductive reasoning aims at validity. In a deductively valid inference, it is inconceivable for the premises to all be true and the conclusion false. ‘(Chimosso 2011 p.180)
127 our experts are availableright now
Chimosso goes on to explain that this type of reasoning deals with relations of ideas. And relates to the abstract sciences, such as mathematics, geometry and algebra. In these cases, observation is not required. We do not need to observe, or indeed cannot observe that 2 multiplied by 6 equals 12. We know this to be indisputably true.
This type of reasoning is called a priori, ‘meaning knowledge that can be gained without reliance on evidence from the senses. (Chimisso p.179). Furthermore, deductive reasoning requires no further investigation, other than to be sure that the premises are correct. If a deductive argument has a false, premise or premises then the conclusion can either be true or false. A premise can be defined as being ‘ ‘something that you suppose is true that you use as a basis for developing an idea ‘ (Collins dictionary online) and, a conclusion as ‘a statement that purports to follow from another or others (the premises) by means of an argument.’ (Collins dictionary online)
When investigating deductive reasoning, it is necessary to ensure firstly that the argument is valid, and secondly it is sound. A valid argument can be defined as follows ‘to say that an argument (or an inference in an argument) is valid is to say that it is guaranteed to be truth preserving: if the premises are true then this truth is bound to carry over to the conclusion. (Another common way of defining ‘validity is in a valid argument; it is absolutely impossible for all the premises to be true without the conclusion being true.) (Chimisso 2011 p.182).
Once validity is established, we can then go on to establish whether an argument is sound, defined as ‘an argument is sound if it’s premises are true and the inference from them to its conclusion is valid. ‘(Chimisso 2011p. 182). Hume found that there are limits to the use of deductive argument. When thinking of, or discussing the world around us and its nature, we cannot rely on deduction, therefore we view and make sense of the world inductively. Meaning, that, when, the senses are used to establish the premise, that the conclusion is not guaranteed to be true.
Inductive reasoning leads to inferred conclusions, meaning that the conclusion does not necessarily follow from the premises. An example of which might be that all observed blue cheese smells strongly. (Premise), therefore all blue cheese observed and unobserved smells strongly.(Generalised conclusion) Hulme maintains that it would not be possible to be certain of this inference, there could have been unobserved blue cheese in the past, or now in the present, or may be in the future, that does not conform to this inference. As a result of this argument, Hume maintains that to make inferences from past to future is irrational. Another way to explain this, is to say that inductive reasoning does not necessarily preserve the truth, as it is not reliable.
This problem with this, is that if we repeatedly observe an event, we then normally expect, through inference, to experience the same event in the future. An example might be, if every time I eat meat, I get severe indigestion, then it is reasonable to expect that if I eat meat in future, I am going to get indigestion. One day for whatever reason I eat a piece of meat. I don’t get indigestion, maybe I didn’t know that I was eating meat and the problem with indigestion had been psychosomatic. Or I had previously only eaten processed meat and was affected by the various hormones, chemicals et cetera, whilst the piece I have just eaten was organic, and didn’t affect me in the usual way. These examples show that it is normally necessary, in inductive reasoning to establish the truth of the premises in order to have confidence in the conclusion.
We need to make use of inferences in order to understand everyday life. Without doing so, every experience would be new, and we would not be able to acquire knowledge. Though in this essay it is past to future inference that is under discussion, there are also other forms of inductive reasoning that are used daily, one of the most important of which is observed to unobserved.
‘Conclusions from experience of cause and effect are not founded on reasoning or any process of the understanding ‘(Hume in Cottingham 2008 p. 434). This refers to inferences made from past experience to future experience. ‘This leads Hume to question the whole approach to inductive reasoning, to be able to reason in this manner, we have to do rely on previous experience which means that we are basing our justification of what we intend to justify. This means that we justify induction by using induction, our argument becomes circular ;(Chimisso 2011p. 72). The accuracy of any conclusion based on experience is dependent on the type of experience. Those based on relationship and social interaction are unlikely to have a high degree of certainty. Due to the high degree of variables involved. Whereas those based on ‘scientific fact ‘have a much higher degree of accuracy.
Hume says that If we consider an object, we can use our senses to gain knowledge of its observable properties but cannot determine any hidden properties of the object. For example, if we hear a guitar being played and find it to be a pleasurable experience, it does not mean that the same guitar played in the future will be pleasant to hear. The guitar may now be out of tune. This is one of Hume’s major objections to the rationality of past to future inference, it is based on an unjustified assumption that the guitar is in tune, that is that the guitar I have listened to is tuned in the same way as the guitar I listened to in the past. Hume said that there is no reason for it to be so as there is no rational justification for it.
A major problem with Hume’s argument against induction is that it calls into question many beliefs, or even established scientific facts. This caused problems amongst fellow philosophers. One of the main critics was Karl Popper who set out to show that science relied on deductive, rather than inductive reasoning. In his view, science relied on observation and experiment to make inferences. This relied on conjecture. In that, if for instance, in the past when sodium has been mixed with water, there was a strong exothermic reaction.
It is possible to conjecture that every time this procedure is carried out, there will be a strong exothermic reaction. It is not impossible that sodium or water with different properties will be found in the future, giving a different reaction. Popper went on to look at science as a deductive rather than inductive process. Instead of premises he used conjecture. This change of approach allowed him to expound the difference between the inductive and deductive approaches.
As we have seen, an inductive approach, seeks confirmation of its conclusion, e.g. every time I have boiled an egg for five minutes it has been hard-boiled. This gives confirmation of that conclusion, reinforcing my belief or expectation in that conclusion, it is reasonable then for me to expect this the next time I boil an egg. However, if atmospheric pressure or purity of the water changes, so will the boiling point, which will have an impact on the length of time required to boil the egg.
As stated, Popper uses a deductive approach, regarding the use of conjecture, then rather than seeking confirmation of the conjecture, in the same way as induction, exceptions are looked for in order to prove the conjecture false. Until the conjecture is falsified then it can be seen to be scientific fact. Once falsified, investigation is carried out and the conjecture changed in the light of the new findings. Whereas with induction, it can often be convenient for scientists to turn a blind eye to exception or to modify the theory to allow for the exception.
If he had been able to, Hume would probably have responded to this point by saying that the use of inductive reasoning should not be denied. He saw that it would be very difficult to survive without it. He would though have maintained his view of its irrationality. He questions his own view by looking at this both as an agent and as a philosopher. ‘As an agent it is reasonable that inference would be part of his daily life. As a philosopher it is reasonable for him to question its rationality ‘. (Hume in Cottingham 2008, P437)
As stated in the introduction, I agree with Hume’s view that past to future inference is not rational, it is easy to observe that animals can apply a form of past to future inference. This inference is not based on reasoning, animals other than possibly the higher primates are not capable of reasoning in the same way that humans are. Therefore, to be able to apply past to future inference, they can only be relying on, as Hume has said, experience. The same thing applies to humans, in that we build expectation from experience. An example might be that for the past several years, I have been to Spain on holiday. I had a great time on each occasion. I expect that I will have a great time on my next holiday. But it is possible that the weather could be bad, or I may become ill with food poisoning, or for some other reason do not enjoy the holiday.
This leads me to support Hume’s view, because for past to future inference to be rational, then all conditions involved must be identical, or at least have a high degree of similarity.
In summary, the two types of reasoning, deductive and inductive have been outlined. The difference between them has been examined, as has Hume’s view of reasoning, in that deductive reasoning is used in terms of relations of ideas, and that inductive reasoning deals with matters of fact. Past to future inference within inductive reasoning and Hume’s concern regarding this. Showing that Hume regarded past to future inference as being irrational. He does, however, recognise that there is a need for the use of this form of inference within everyday life, but as a philosopher questions its rationality. Popper’s objection to the use of inductive reasoning in the sciences a potential response from Hume was discussed.
I agree with Hume as set out above. Because, in order to be able to make an inference, conditions must stay the same, it is a characteristic of nature that there is constant change at every level within nature. Change is the nature of nature
