Logic
One of the main focuses of Aristotle’s philosophy was his systematic concept of logic. Aristotle’s objective was to come up with a universal process of reasoning that would allow man to learn every conceivable thing about reality. Aristotle introduced the concept of deduction as a reasonable argument in which “when certain things are laid down, something else follows out of necessity in virtue of their being so.” This was the Basis of syllogism, “a logical argument where the conclusion is inferred from two or more other premises of a certain form.” Angie Lewis
Aristotle writes:
In the case of rhetoric there were many old writings on which to draw upon, but in the case of logic we had absolutely nothing at all to mention until we had spent much time in laborious research.
The two treatises of Aristotle on logic are the Prior Analytics and the Posterior Analytics. Prior Analytics deals with sets of statements that use letters as undefined variables in order to see whether a deduction is valid or not from a set of statement’s, while the Posterior Analytics applies this method to science.
Aristotle discusses what can be inferred from a certain set of truths. Using words such as “all,” “no,” and “some,” he made inferences from the statements. For example:
All dolphins are mammals
All mammals are warm blooded
Therefore all dolphins are warm blooded
Some humans swim in the sea
therefore humans are fish
All fish can breathe under water
Humans can breathe under water
Aristotle writes:
In the case of rhetoric there were many old writings on which to draw upon, but in the case of logic we had absolutely nothing at all to mention until we had spent much time in laborious research.
The two treatises of Aristotle on logic are the Prior Analytics and the Posterior Analytics. Prior Analytics deals with sets of statements that use letters as undefined variables in order to see whether a deduction is valid or not from a set of statement’s, while the Posterior Analytics applies this method to science.
Aristotle discusses what can be inferred from a certain set of truths. Using words such as “all,” “no,” and “some,” he made inferences from the statements. For example:
All dolphins are mammals
All mammals are warm blooded
Therefore all dolphins are warm blooded
- If the first two statements are true, then the inference will always be correct.
- One or more of the initial statements are false
- You arrive at a false inference from two correct statements
Some humans swim in the sea
therefore humans are fish
- although the first two statements are true, the inference is not
All fish can breathe under water
Humans can breathe under water
- the inference is correctly obtained from the statements, but as one of the statements is false, the inference is wrong