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Philosophy

<OpenstaxParagraph>
	When thinking about values, it can be easy to make errors. A <OpenstaxTerm>fallacy</OpenstaxTerm> is an error in logical reasoning. Fallacies involve drawing the wrong conclusions from the premises of an argument or jumping to a conclusion without sufficient evidence. There are many types of logical fallacies because there are many ways people can make mistakes with their reasoning.
</OpenstaxParagraph>
<OpenstaxNote>
	<OpenstaxNoteTitle> Connections </OpenstaxNoteTitle> 
	<OpenstaxParagraph>
		Learn more about informal fallacies in the chapter on <a href="./fe58be6f-3b61-4e16-b3b6-db6924f0b2f2@a904be0:2ef161f6-f767-4478-a452-bfe94fbc4022.xhtml">logic and reasoning</a>, and explore more about cognitive values in the chapter on <a href="./fe58be6f-3b61-4e16-b3b6-db6924f0b2f2@a904be0:1847b0a0-763b-4763-ac86-c17e70efb05b.xhtml">critical thinking, research, reading, and writing</a>.
	</OpenstaxParagraph>
</OpenstaxNote>
<OpenstaxParagraph>
	The <OpenstaxTerm>naturalistic fallacy</OpenstaxTerm> is an error in reasoning that assumes you can derive values (what people <OpenstaxEm>ought</OpenstaxEm> to do) from facts about the world (what <OpenstaxEm>is</OpenstaxEm> the case). The British philosopher G. E. <OpenstaxTerm>Moore</OpenstaxTerm> (1873–1958) explains the problem with this fallacy in his 1903 book <OpenstaxEm>Principia Ethica</OpenstaxEm>. For Moore, if philosophers based the judgment “x is good” on a set of facts, or natural properties, about x, they have committed the naturalistic fallacy.
</OpenstaxParagraph>
<OpenstaxParagraph>
	There are frequent examples of the naturalistic fallacy in popular discourse. Debates about whether monogamy is good or bad are frequently posed in terms of whether it is “natural,” and proponents for either side of the argument often point at monogamous or nonmonogamous animals to justify their answer. Claiming what humans ought to do from observations about animal behavior is an attempt to derive values from facts about the world.
</OpenstaxParagraph>
<OpenstaxH3>Hume and the Is-Ought Problem</OpenstaxH3>
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	The naturalistic fallacy is related to <OpenstaxTerm>the is-ought problem</OpenstaxTerm>. This problem asserts the challenge of moving from statements of fact (something <OpenstaxEm>is</OpenstaxEm>) to statements of value (something <OpenstaxEm>ought</OpenstaxEm> to be). The Scottish Enlightenment philosopher <OpenstaxTerm>David Hume</OpenstaxTerm> (1711–1776) provides one of the most famous explanations of this problem in his <OpenstaxEm><OpenstaxTerm>A Treatise of Human Nature</OpenstaxTerm></OpenstaxEm> (1739–1740).
</OpenstaxParagraph>
<OpenstaxFigure id="fig-00001" src="https://openstax.org/apps/archive/20240226.174525/resources/4da82cde14e7c09abb2d06555f5e3522d586452b" alt="A lounging domestic cat looks directly at the viewer." mediaType="image/jpeg" width="800" height="533" />
<OpenstaxFigureText width="800">
	<strong>Figure 8.2</strong> The descriptive claim “Having pets has been shown to improve people’s mental health” can easily become the evaluative claim “People ought to have pets.” This is known as the is-ought problem. (credit: “My cat Toby” by Richard J/Flickr, Public Domain)
</OpenstaxFigureText>
<OpenstaxParagraph>
	At the time Hume was writing the <OpenstaxEm>Treatise</OpenstaxEm>, philosophers were rejecting a morality based on religious faith or dogmatic beliefs and were instead trying to find justifications for morality that relied on undeniable reasons for being a good person or trying to build a better society. Hume countered that you cannot derive <OpenstaxEm>ought</OpenstaxEm> from <OpenstaxEm>is</OpenstaxEm> because morality has to do with sentiments, not facts. In other words, morality has to do with what people believe and how we feel, and beliefs and feelings are not factual or derivable from facts. As Hume explains in the passage below, facts have to do with relations between objects. Morality, however, has to do with a human subject expressing their sentiments about a matter.
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<OpenstaxNote>
	<OpenstaxNoteTitle> Read Like a Philosopher </OpenstaxNoteTitle> 
	<OpenstaxParagraph>
		Read this excerpt from David Hume’s <OpenstaxEm>A</OpenstaxEm> <OpenstaxEm>Treatise of Human Nature</OpenstaxEm>, Book 3, Part 1. As you read, pay attention to how he describes propositions that use “ought.” Does he seem to think they are justified with proper reasoning? Why or why not? Think of an example where using “ought” statements without rational justification could be a problem.
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			“I cannot forbear adding to these reasonings an observation, which may, perhaps, be found of some importance. In every system of morality, which I have hitherto met with, I have always remarked, that the author proceeds for some time in the ordinary way of reasoning, and establishes the being of a God, or makes observations concerning human affairs; when of a sudden I am surprized to find, that instead of the usual copulations of propositions, is, and is not, I meet with no proposition that is not connected with an ought, or an ought not. This change is imperceptible; but is, however, of the last consequence. For as this ought, or ought not, expresses some new relation or affirmation, it is necessary that it should be observed and explained; and at the same time that a reason should be given, for what seems altogether inconceivable, how this new relation can be a deduction from others, which are entirely different from it. But as authors do not commonly use this precaution, I shall presume to recommend it to the readers; and am persuaded, that this small attention would subvert all the vulgar systems of morality, and let us see, that the distinction of vice and virtue is not founded merely on the relations of objects, nor is perceived by reason.”
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	<OpenstaxParagraph>
		(Source: Hume, David. (1739–1740) 2002. <OpenstaxEm>A</OpenstaxEm> <OpenstaxEm>Treatise of Human Nature</OpenstaxEm>, Book III, Part I, Section I. Project Gutenberg. https://www.gutenberg.org/files/4705/4705-h/4705-h.htm - link2H_4_0085)
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<OpenstaxH3>The Open-Question Argument</OpenstaxH3>
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	Hume’s description of the is-ought problem lives on in contemporary philosophy, especially in 20th-century ethics. In his 1903 book <OpenstaxEm>Principia Ethica</OpenstaxEm>, G. E. <OpenstaxTerm>Moore</OpenstaxTerm> introduces the <OpenstaxTerm>open-question argument</OpenstaxTerm> to argue against the naturalistic fallacy, which he sees as trying to derive non-natural properties, such as “right” and “good,” from natural properties. Unlike claims in the natural sciences, which extend understanding of or express a discovery about natural properties of the world, goodness and rightness are non-natural properties that cannot establish their truth based on natural properties and thus are always open to questioning. For example, the natural properties of water (H<sub>2</sub>0) are not open to questioning in the same way that the non-natural properties of things that people judge to be “good” or “right” are.
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<OpenstaxParagraph>
	In order to answer the question “Is x good?” people frequently have to assert that something else is good. Is being kind to your neighbor good? Yes. Why? Because compassion for others is good. This does not “close” the question because it amounts to saying “good is good.” It is circular and thus uninformative, so the question remains open. Moore did believe that claims about moral properties can be true, but not in the same way as claims about natural properties.
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<OpenstaxNote>
	<OpenstaxNoteTitle> Read Like a Philosopher </OpenstaxNoteTitle> 
	<OpenstaxParagraph>
		Search social media platforms for examples of “is” presented as “ought” statements. What types of beliefs do you notice people presenting as facts? What types of justifications are given for these claims?
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8.1.2 The Naturalistic Fallacy

1 Introduction to Philosophy

1.1 What Is Philosophy?

1.1.1 Historical Origins of Philosophy

1.1.2 How It All Hangs Together

1.2 How Do Philosophers Arrive at Truth?

1.2.1 Sources of Evidence

1.2.2 Logic

1.2.3 Conceptual Analysis

1.2.4 Trade-offs

1.3 Socrates as a Paradigmatic Historical Philosopher

1.3.1 “The Life Which Is Unexamined Is Not Worth Living”

1.3.2 Human Wisdom Is Worth Little or Nothing

1.3.3 The Importance of Doing No Harm

1.4 An Overview of Contemporary Philosophy

1.4.1 What Can You Do with a Philosophy Major?

1.4.2 An Overview of Your Philosophy Textbook

2 Critical Thinking, Research, Reading, and Writing

2.1 The Brain Is an Inference Machine

2.1.1 The Brain’s Adaptive Ability to Plan Ahead

2.1.2 The Evolutionary Advantage of Shortcuts

2.2 Overcoming Cognitive Biases and Engaging in Critical Reflection

2.2.1 Critical Reflection and Metacognition

2.2.2 Cognitive Biases

2.3 Developing Good Habits of Mind

2.3.1 Strive for Objectivity

2.3.2 Adopt Epistemic Humility

2.4 Gathering Information, Evaluating Sources, and Understanding Evidence

2.4.1 Start with a Strong Foundation

2.4.2 The SIFT Method (Four Moves for Student Fact Checkers)

2.5 Reading Philosophy

2.5.1 Prepare to Read

2.5.2 Engaging with Philosophical Texts

2.5.3 Pre-reading

2.5.4 First Read

2.5.5 Close Read

2.6 Writing Philosophy Papers

2.6.1 Identify Claims

2.6.2 Collect Evidence and Build Your Case

2.6.3 Organize Your Paper

3 The Early History of Philosophy around the World

3.1 Indigenous Philosophy

3.1.1 Challenges in Researching Indigenous Philosophy

3.1.2 Indigenous African Philosophy

3.1.3 Indigenous North American Philosophical Thought

3.1.4 Mesoamerican Philosophy

3.2 Classical Indian Philosophy

3.2.1 The Vedic Tradition

3.2.2 Classical Indian Darshanas

3.3 Classical Chinese Philosophy

3.3.1 Early Chinese Philosophical Thought prior to Confucius

3.3.2 Confucianism

3.3.3 Daoism

3.3.4 Mohism

4 The Emergence of Classical Philosophy

4.1 Historiography and the History of Philosophy

4.1.1 Presentist Approach

4.1.2 Contextualist Approach

4.1.3 Hermeneutic Approach

4.2 Classical Philosophy

4.2.1 Egyptian Origins of Classical Philosophy

4.2.2 Ancient Greek Philosophy

4.2.3 The Presocratics

4.2.4 Socrates and Plato

4.2.5 Aristotle

4.2.6 Epicureans

4.2.7 Roman Philosophy

4.3 Jewish, Christian, and Islamic Philosophy

4.3.1 Defining Jewish, Christian, and Islamic Philosophy

4.3.2 Early Jewish Philosophy

4.3.3 Early Christian Philosophy

4.3.4 Islamic Philosophy

4.3.5 Late Medieval Philosophy in Christian Europe

4.3.6 Jewish Philosophers in the Christian and Islamic Worlds

4.3.7 The Rise of Reason in the Early Modern Era

5 Logic and Reasoning

5.1 Philosophical Methods for Discovering Truth

5.1.1 Dialectics and Philosophical Argumentation

5.1.2 The Use of Reason to Discover Truth

5.1.3 Testing Hypotheses

5.1.4 Laws of Logic

5.1.5 Normativity in Logic

5.2 Logical Statements

5.2.1 Conditionals

5.2.2 Universal Statements

5.3 Arguments

5.3.1 Getting to the Premises

5.3.2 The Difference between Truth and Logic

5.4 Types of Inferences

5.4.1 Deductive Reasoning

5.4.2 Inductive Inferences

5.4.3 Abductive Reasoning

5.5 Informal Fallacies

5.5.1 Fallacies of Relevance

5.5.2 Fallacies of Weak Induction

5.5.3 Fallacies of Unwarranted Assumption

5.5.4 Fallacies of Diversion

6 Metaphysics

6.1 Substance

6.1.1 Fundamentality: The One and the Many

Question	Answer
an error in logical reasoning—for example, jumping to a conclusion without proper evidence.	Fallacy
an error in reasoning that assumes one can derive values (what people ought to do) from facts about the world (what is the case).	Naturalistic fallacy
G. E. Moore’s argument against the naturalistic fallacy, which he sees as trying to derive non-natural properties from natural properties. For Moore, arguing that something is “good” (a non-natural property) based on natural properties is circular and leaves an open question.	Open-question argument