Anil Kumar Tewari
The common test paper of UGC (NET) includes 4 – 6 questions on the understanding of the nature of reasoning. Some questions of Assertion-Reason type are also asked. This portion is meant to test the candidates’ ability to appreciate and formulate convincing arguments. The objective of the following discussion is to guide the aspirants in regard to the above section and also to generate curiosity among them for the essential activity undertaken in learning philosophy as an academic discipline. Let us begin with a general definition of argument. An argument is generally defined as a group of statements (i.e. propositions) in which one statement is claimed to follow from the other statement(s). For instance, on the acceptance that ‘All cats are animal’ and ‘All ragdolls are cats’, one can logically claim that ‘All ragdolls are animals’. The first two statements are meant to provide support to the last statement. In any argument, the ‘supported statement’ is called conclusion and the ‘supporting statement’ is called premise.
There are certain markers which indicate that a particular group of statements forms an argument. In order to identify an argument, we must find out whether there is a conclusion in the given group of statements. The conclusion-statement of an argument is normally identified as the statement which follows the expressions such as ‘therefore’, ‘accordingly’, ‘entails that’, ‘we may conclude’, ‘hence’, ‘thus’, ‘it must be that’, ‘it follows that’, ‘consequently’, ‘for this reason’, ‘implies that’, ‘we may infer’, ‘so’, ‘as a result’. If conclusion is not identified in need of such expressions, we should proceed to point out which statement(s) cannot be the conclusion. The statements which are joined with the expressions such as ‘and’ ‘since’, ‘in that’, ‘seeing that’, ‘as indicated by’, ‘may be inferred from’, ‘for the reason that’, ‘because’, ‘as’, ‘in as much as’, ‘for’, ‘given that’, ‘owing to’ cannot be the conclusion. For, these expressions are the reasons or justifications on which certain claim is made/to be made. It is the claim or the supported statement which is called conclusion. Such statement is sometimes written without any indicator and the premise-indicators by exclusion suggest the conclusion-statement.
Once ‘conclusion’ and ‘premises’ are identified in a passage, one can say that this group of statement is an argument. The relation between the premises and conclusion is called ‘implication’. There are various expressions used to represent this relation: ‘the premises imply/entail the conclusion, ‘the conclusion is implied/entailed by the premises’, ‘the conclusion follows from the premises’ etc. The strength of this relationship determines the nature of an argument. Arguments are classified into ‘deductive’ and ‘inductive’ category. The classification depends on the strength of the relationship obtained between the premises and conclusion. If they are so related that the conclusion is claimed to follow absolutely or conclusively from the premises, the argument is called deductive argument. For example,
P1: All the followers of Jainism are vegetarians.
P2: Sudhir Jain is a follower of Jainism.
C: Therefore, Sudhir Jain is a vegetarian.
The structure of the above argument suggests that the premises P1 and P2 provide complete or absolute support to the conclusion C. The logical meaning of the absolute support comes from the intuition that one cannot rationally deny the conclusion if one accepts the premises. In other words, if the premises are true, the conclusion cannot be false. It is this strong bond between the premises and conclusion which makes an argument deductive.
Consider another argument:
P1: All cats are humans.
P2: All ragdolls are cats.
C: Therefore, all ragdolls are humans.
In this argument, one can easily deny the conclusion that ‘All ragdolls are humans’ since ragdoll is a breed of cat. But this is not a logical denial. One can simply notice that the structure of the Jainism argument and this argument is the same. Therefore, the logical worth of both the arguments must be the same. That is, one cannot logically deny the authenticity of conclusion if one sincerely believes in the trueness of premises. This is called absolute support of the premises to its conclusion. And the arguments which maintain such support are called deductive arguments. If the claimed complete support is found to be genuine, the deductive argument is called ‘valid argument’. The arguments mentioned above are the instances of a valid argument. On the contrary, if the claim is not a genuine one, the deductive argument is called invalid argument. The following is an example of an invalid argument:
P1: All cats are non-vegetarians.
P2: All cats are animals.
C: Therefore, all animals are non-vegetarians.
This argument is invalid, because one can accept the premises but deny the conclusion without any logical difficulty. In common sense language, ‘all cats are animals’ does not mean ‘all animals are cats’. If it were so, the argument could have been a valid one. We will learn the structures of arguments and the logical rules to decide their validity in the coming entry.
In an inductive argument, the conclusion is not claimed to be absolutely supported by the premises. Instead, the strength of the claimed support is less than absolute. It could be very strong or weak but not absolute or complete. Inductive arguments thus involve probabilistic reasoning. For example, ‘Sudhir took curd and he got acidity’, ‘Manoj took curd and he got acidity’, therefore, ‘Curd causes acidity’. Here one cannot with complete certainty say that curd is the reason behind the problem of acidity; instead, curd can be called a probable cause of acidity as suggested by limited observations. It is possible that the acidity is caused by some other food items or there could be other examples of curd-eating without having the problem of acidity. Therefore, the link between the conclusion and the premises is not very convincing. All the theories of sciences are good examples of strong inductive arguments, they are convincing so long as they work, but their conclusions are falsifiable or susceptible to revision. The inductive arguments with strong bond between the conclusion and premises are called cogent arguments. There are certain indicators which can be used to denote inductive conclusions such as ‘probable’, ‘improbable’, ‘plausible’, ‘implausible’, ‘likely’, ‘unlikely’, ‘reasonable to conclude’. Some more markers of deductive conclusions are ‘certainly’, ‘absolutely’, ‘definitely’, ‘conclusively’ etc. The following is the analysis of a question asked in June 2014 test:
Question: Given below are some characteristics of logical argument. Select the code which expresses a characteristic which is not of inductive in character. The options were: (A) The conclusion is claimed to follow from its premises, (B) The conclusion is based on causal relation, (C) The conclusion follows conclusively from its premises, and (D) The conclusion is based on observation and experiment. Analysis: The question is to point out the option describing the character of only deductive argument (‘not inductive’ is taken to mean ‘deductive’ given the bicameral division of arguments in deductive and inductive). The option (A) tells a general feature of an argument applicable to both deductive as well as inductive. The option (B) and (D) tell essentially the same thing since cause-effect relation is also based on observation. Thus, by exclusion option (C) is correct. Moreover, the C option also includes the expression ‘conclusively’, which is indicative of the character of a deductive argument. The second entry in this sequence will discuss the nature of categorical proposition.
(The author is an assistant professor of philosophy in the School of Philosophy & Culture, SMVDU)
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