Proving a Thesis – Logic


inductive leap

inductive reasoning

hasty generalization

deductive reasoning



major premise

minor premise


valid argument

sound argument

Toulmin Logic




logic – evidence should be evaluated for logic; does the evidence have any logical fallacies

inductive reasoning – logic that draws a generalization from a particular piece of information; subject to error since the particular observation is not necessarily representative of a larger group. Since there is one rotting apple in the bag, all the apples must be rotting. See Logical Fallacies and Appeals. link

inductive leap – the jump from the particular to a universal rule

hasty generalization – the term applied to the erroneous result from an inductive leap; one of the logical fallacies

deductive reasoning – logic that draws a conclusion about a particular situation from a general rule; more likely to result in an accurate conclusion since a general rule usually applies to all situations within its category: All flowers need water; therefore, petunias need water.

self-evident – evidence that is apparent by observation or reasoning

syllogism – a three-part sequence of reasoned thoughts to draw a logical conclusion: All flowers need water. Petunias are flowers. Petunias need water.

major premise – the general or universal assumption used to make a logical analysis: All flowers need water. Note that if a major premise is not accurate, the resulting conclusion will not be accurate although it may be logical.

minor premise – the assumption pertaining to an example in the major premise: Petunias are flowers. Not that if a minor premise is not accurate, the resulting conclusion will not be accurate although it may be logical.

conclusion (logical conclusion) – the resulting logical thought of analyzing the major and minor premise; logical conclusions are not necessarily true or accurate.

valid argument – an argument which is based on logical analysis of information; not necessarily true

sound argument – an argument based on a syllogism that has accurate major and minor premises

Toulmin Logic – a form of logic that uses claim, grounds, and warrant for analyzing the logic of an argument

claim – the thesis; the point that is to be proved in Toulmin Logic

grounds – the evidence (proof, support) for the claim in Toulmin Logic

warrant – the result assumption of an analysis of claim and grounds in Toulmin Logic.

See also Logical Fallacies (Flawed Logic) and Appeals.