logic - the science of methods, laws and forms of thinking.Formal logic has been developed by the ancient Greeks long before our era.It was the first Greeks to build a democratic society where laws and decisions taken at the National Assembly.They have created a primitive science of litigation.A favorite pastime of the aristocratic youth had discussions with philosophers.Hence the universal love for the development of theoretical science.Greeks just had the doctrine of how to be scientific evidence.
first course the basics of logic developed by Aristotle.He drew attention to the fact that all the arguments are based on the common law, the violation of which leads to erroneous conclusions.The formal logic of Aristotle was based on these laws:
- If judgments are affirmative, what to make of them the conclusion can not be negative.
- If one of the statements is negative, and the general conclusion will always be negative.
It appears that formal logic - a knowledge of the principles and laws effectively, proper construction of reasoning with regard to the shape of their construction (ways of connecting parts of general considerations).
All phenomena and objects have a relationship.Links can be objective or subjective, shared or private, necessary or accidental.The most significant of these bonds are called laws.They all reflect the same reality, therefore, can not contradict each other.All the laws of human thought are linked to the laws of nature.
laws of thought are stable inner connection between thoughts.If a person can not bind his thoughts, he did not come to the right conclusion and will not be able to bring it to others.
basic laws of formal logic - the laws of consistency, the identity, the excluded middle and the law of sufficient reason.The development of the first three belong to Aristotle and Plato, the last - Leibniz.Violations of these laws (especially the first three) leads to contradictions, making it impossible to distinguish truth from falsehood.Last less regulations and the law applies more limited.
Non-core laws of logic - is the rules of operating concepts and judgments, obtaining true conclusion in a syllogism, increasing the probability of inductive reasoning and conclusions traduktivnogo character.
Act consistency means that thinking should not be controversial, and should reflect the quality of certain things.
law of the excluded middle requires not look between the two conflicting but true statement a third thing, and to acknowledge the truth of only one of them.One of the components of the conflict - certainly true.
law of formal logic treats identity as a requirement of precision thinking, ie from any term you need to understand exactly its definition and meaning.The essence of the concepts and judgments can not distort at will.
law of sufficient reason is that any true thought necessary to justify the true thoughts of others, and false ideas can not be justified.In the development of judgments should reflect a causal relationship.Only in this case it can be proven reliability.
logical form of thought and ways of defining any form of thoughts expressed by logical terms, which include the word "and", "or", "if ... then ..." denial "is not true that"(" no "), the word" some "," all "(" no "), a bunch of" essence "(within the meaning of" is "), etc.Identify the logical form of judgment can be distracted from the meaning of the terms of illogical that are verbal expression of this judgment.In other words, formal logic expresses the structure of thought.Logical form is always informative and meaningful.
Depending on their forms of thought are divided into classes: the concepts, reasoning and judgment.The concept - the idea generalizes objects on the basis of their basic characteristics.Judgment - the idea, asserting the presence (absence) of the situation.Inference - thought, reflecting the acquisition of knowledge as expressed in the judgments of other knowledge.
