Key words - ad hominem, begging the question, belief bias, loaded questions, premise, rationalism, syllogism, vested interest, infinite regress, vicious circle
Deductive reasoning - Any form of reasoning that moves from the general to the particular
Truth and validity - Truth is concerned with what is the case, validity with whether conculsions follow from premises; truth is a property of statements, validity of arguments.
Inductive reasoning - Inductive reasoning goes from the particular to the general.
Informal reasoning - post hoc ergo propter hoc - assumes that because one thing follows another, the latter is the cause of the former.
Ad hominem - consists in attacking or supporting the person rather than the argument
Circular reasoning - consists in assuming the truth of something that you are supposed to be proving.
Ad ignorantium - is claiming something is true on the grounds that there is no evidence to disprove it
The importance of premises - If the truth of the conclusion depends on the truth of the premises, then we need to take a close look at what we use as premises
Reason and certainty -
Lateral thinking - Edward de Bono suggests that - since we cannot rely on traditinal logic to give us new ideas, we need to adopt a more creative way of thinking that encourages us to search actively for better solutions to problems
Universal generalizations: precious, fragile statements
Is there more to rationalism than logic? According to some thinkers,logic has traditionally been seen as the academic's way of repairing the cognitive errors of the stupid....
Causal inference - Inference is a powerful move in reasoning: filling in the connections between pieces of information we already have, taking statements we already believe and from them pulling out more.
Classification - Classification is a form of reasoning that groups concepts, ideas, and objects together into related categories, and gives them a collective term
‘It has been said that man is a rational animal. All my life I have been searching for evidence which could support this.’ Bertrand Russell
'I do not feel obliged to believe that the same God who has endowed us with sense, reason, and intellect has intended us to forgo their use.' Galileo Galilei
'He that will not reason is a bigot; he that cannot reason is a fool; and he that dares not reason is a slave.' William Drummond
'Critical reason is the only alternative to violence so far discovered.' Karl Popper
'Reason itself is a matter of faith. It is an act of faith to assert that our thoughts have any relation to reality at all.' G K Chesterton
'You do not reason a man out of something he was not reasoned into' Jonathan Swift
?? What is the difference between reason and logic?
?? How reliable is inductive reasoning?
?? What is the difference between a prejudice, a generalisation and a scientific law ?
?? Is there a clear distinction between logical reasoning and 'everyday' 'common' thinking? If so, is the former superior to the latter?
?? What is the difference between being irrational and being insane? How irrational must someone be before you classify them as insane?
?? What constitutes a "good reason" for belief?
?? Is a persuasive reason necessarily grounded in truth?
?? Does all knowledge require some kind of rational basis?
?? Why is reason so hard to accept?
?? How do we really make decisions?
?? Are faith and reason mutually incompatible?