deductive reasoning

Examples of deductive reasoning in the following topics:

• Different Lines of Reasoning

  • Apply two different lines of reasoning—inductive and deductive—to consciously make sense of observations and reason with the audience.
  • Deductive reasoning, also called deductive logic, is the process of reasoning from one or more general statements, laws, or principles regarding what is known, in order to reach a logically certain conclusion.
  • Deductive reasoning involves using given, true premises to reach a conclusion that is also true.
  • Deductive reasoning contrasts with inductive reasoning in that a specific conclusion is arrived at from the general principle when reasoning deductively.
  • Notice that inductive reasoning moves from specific instances to a general conclusion, whereas deductive reasoning applies a general principle to specific instances.

• Logic

  • Aristotle (384-322BCE) is usually credited with formalizing syllogistic or deductive reasoning.
  • Deductive reasoning is a process that starts with a set of premises (or a priori truths) or general principles and through rules of logic, "deduces" a conclusion about a specific case.
  • The differences are that abduction is less formal process that consists of a combination of intuition, experience, observation, deductive reasoning and generates hypotheses which could be wrong.
  • Abduction is the insight that occurs with less conscious formal reasoning than either induction or deduction.
  • It is the purpose of inductive and deductive reasoning to test the hypotheses that emerge from the process of abduction.

• Reasoning and Inference

  • Deductive reasoning has the advantage that, if your original premises are true in all situations and your reasoning is correct, your conclusion is guaranteed to be true.
  • However, deductive reasoning has limited applicability in the real world because there are very few premises which are guaranteed to be true all of the time.
  • A syllogism is a form of deductive reasoning in which two statements reach a logical conclusion.
  • In this video, we see the famous literary character Sherlock Holmes use both inductive and deductive reasoning to form inferences about his friends.
  • Can you distinguish between his deductive (general to specific) and inductive (specific to general) reasoning?

• Scientific Reasoning

  • To do this, they use two methods of logical thinking: inductive reasoning and deductive reasoning.
  • Deductive reasoning or deduction is the type of logic used in hypothesis-based science.
  • In deductive reason, the pattern of thinking moves in the opposite direction as compared to inductive reasoning.
  • Deductive reasoning is a form of logical thinking that uses a general principle or law to forecast specific results.
  • Scientists use two types of reasoning, inductive and deductive, to advance scientific knowledge.

• Reasoning

  • We use many mental shortcuts when conducting inductive, deductive, abductive, and analogous reasoning to find a solution to a problem.
  • In order to solve problems, we utilize four major forms of reasoning: deduction, induction, abduction, and analogy.
  • Deduction is the process of reasoning from one or more general statements, known as premises, to reach a logically certain conclusion.
  • Unlike deductive reasoning , it allows for the possibility that the conclusion is false, even if all the premises are true.
  • Unlike deductive reasoning, the premise does not guarantee the conclusion, and is considered an inference to the best explanation.

• Deploying a Rational Appeal

  • Our focus on reasoning and how you to use evidence to reason with your audience is part of the study of logos.
  • Prior to your speech, it is important to consider the soundness of your evidence and reasoning.
  • Deductive reasoning: For example, if you are engaging in deductive reasoning, you will want to consider whether or not the audience is likely to accept the general premise as valid and true before you attempt to deduce other ideas or courses of action based on the general premise.
  • Inductive reasoning: If you are engaging in inductive reasoning, you will want to consider whether you have observed or collected enough evidence to draw a highly probable conclusion.
  • Associative reasoning (analogy): When engaging in associative reasoning, you will want to make sure that the ideas are indeed similar and that there are no obvious or outstanding differences which would negate the association in the mind of your audience.

• Logical Fallacies

  • A fallacy is an error in reasoning; there are two basic categories of fallacies--formal and informal.
  • A fallacy is an error in reasoning.
  • Consider an example with a visualization of faulty reasoning involving categorical deduction.
  • As a speaker you want to carefully consider your reasoning and how you draw your logical conclusions in order to avoid faulty reasoning.
  • The deductive reasoning is valid but the major premise is not valid.

• Elective Expensing

  • Buildings were not eligible for section 179 deductions prior to the passage of the Small Business Jobs Act of 2010; however, qualified real property may now be deducted.
  • Depreciable property that is not eligible for a section 179 deduction is still deductible over a number of years through MACRS depreciation according to sections 167 and 168.
  • The 179 election is optional, and the eligible property may be depreciated according to sections 167 and 168 if preferable for tax reasons.
  • If, for example, the taxpayer's net trade or business income from active conduct of trade or business was 72,500 dollars in 2006, then the deduction cannot exceed 72,500 dollars that year.
  • However, any deduction not allowed in a given year under this limitation can be carried over to the next year.

• S-Corporations (S-Corps)

  • S corporations elect to pass corporate income, losses, deductions, and credit through to their shareholders for federal tax purposes.
  • If for some reason, Bob (as the majority owner) was to decide not to distribute the money, both Bob and John would still owe taxes on their pro-rata allocation of business income, even though neither received any cash distribution.
  • S corporations elect to pass corporate income, losses, deductions, and credit through to their shareholders for federal tax purposes.
  • However, in the manner of a partnership, an S corporation's income, deductions, and tax credits flow through annually to shareholders, regardless of whether distributions are made.
  • Unlike a C corporation, an S corporation is not eligible for a dividends received deduction, nor is it subject to the ten percent of taxable income limitation applicable to charitable contribution deductions.

• Tax Deductions

  • A tax deduction is a reduction of the amount of income subject to tax.
  • What is the after-tax cost of a $1,000 of deductible expense?
  • A tax deduction is a sum that can be removed from tax calculations.
  • Often these deductions are subject to limitations or conditions.
  • While a deduction is a reduction of the level of taxable income, a tax credit is a sum deducted from the total amount of tax owed.