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.

• 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.

• Reasons to Outline

  • There are many reasons to create an outline; but in general, it may be helpful to create an outline when you want to show the hierarchical relationship or logical ordering of information.
  • Justify out the reasons to outline prior to writing a speech or presentation

• Persuasive Speeches on Questions of Fact

  • Is there reason to believe that a source may be biased, either personally or by the thinking prevalent at the time in history?
  • Reasoning: The speaker will usually be dealing with inductive reasoning, in which he or she asks the audience to agree with a conclusion after presenting all of the evidence.

• Types of Supporting Materials

  • Intuition is the ability to acquire knowledge without inference or the use of reason.
  • For this reason, intuition is not a particularly strong supporting material.

• Using Supporting Materials

  • Some audiences are skeptical of non-scientific supporting materials for this very reason.
  • Identify reasons to use supporting materials and which types of materials are appropriate in a given situation

• Listening and Critical Thinking

  • One definition for critical thinking is "the intellectually disciplined process of actively and skillfully conceptualizing, applying, analyzing, synthesizing, and/or evaluating information gathered from, or generated by, observation, experience, reflection, reasoning, or communication, as a guide to belief and action. "
  • Critical thinking occurs whenever people figure out what to believe or what to do, and do so in a reasonable, reflective way.

• Definitions

  • You can define fruit salad as consisting of bananas, pineapples, and yellow apples (ideally you would have a reason for this, too).
  • For example, you can define fruit salad as consisting of bananas, pineapples, and yellow apples (ideally you would have a reason for this, too).
  • For this reason, you should also define the terms carefully.

• Critical Thinking

  • In order to present a clear and well-reasoned argument, you'll need to make sure you have accurate and specific evidence to support your claims.
  • Now that you know all the possible angles from which others can approach your line of reasoning, now it's time to select the best evidence to support your thesis.
  • Critical thinking is more than just the rote study of information and facts; it requires the thinker to reason reflectively about her beliefs and actions regarding those facts and information.