Study Guide Lesson 15: Skepticism and Certainty

Local Skepticism

Local skepticism, by contrast of global skepticism, only questions knowledge claims of a particular kind—metaphysical claims.

Methodological Skepticism

Methodological skepticism employs skepticism in its attempt to gain knowledge but is not skeptical in its conclusions. In this approach, the skeptic uses doubt to weed out all the ideas that are not certain and sure. Once all these ideas have been removed, the clearest, most certain ideas which remain can be affirmed without any reasonable hesitation. Basically any idea that doesn't fit a mental checklist is out and the last left idea which is closest to this checklist is the one that is declared right and true.

Metaphysical Skepticism

This form of skepticism suggests that we can have knowledge of the natural world via science and sense perceptions. But it denies the possibility of gaining any knowledge of the metaphysical realm or metaphysical things. So, for example, it suggests that we can have knowledge of stars, apples, gravity, cardiovascular systems, etc. but holds that we cannot know anything about God, souls or goodness.

Probabilistic Certainty

This is the level of assurance after Absolute Certainty. This includes statements like "The sun will rise tomorrow" or "The pen will fall if I drop it." These statements are considered to be true by everyone. But it is always possible that the sun will not rise tomorrow or that the pen could float on this one occasion. One cannot claim to know with certainty that these things will happen. However, it's foolish to think that these things wouldn't happen based on the fact that they have always happened.

Principle of Causality

This principle states that every effect has a cause. The idea of causality is universally recognized, as we observe it regularly in the world. For example, I accidentally knock a glass over on the table in front of me. If we ask, "What caused the glass to fall over?" the reply would obviously be, "You hit it."

Mitigated Skepticism

This simply believes that no knows anything.

Unmitigated Skepticism

Unmitigated skepticism claims that definitely and dogmatically it knows that no one knows anything. This is obviously self-defeating.

On what basis did Kant believe we were justified in believing in God?

While Kant believed one could not justify a belief in the existence of God on the basis of pure reason, he did believe that one could justify belief on the basis of practical reason. In his Critique of Practical Reason, Kant stated, "Two things fill the mind with ever-increasing admiration and awe—the starry heavens above me and the moral law within me."8 Kant was convinced of the existence of absolute moral laws. He argued that God must exist in order for such laws to make sense. For if good does not win over evil in the end, then moral duties make no sense.

Systematic Doubt

a systematic process of being skeptical about (or doubting) the truth of one's beliefs, used to identify those ideas which are undoubtable.

Explain 4 problems with skepticism.

1. Much of skeptical thought is either self-defeating or impractical. Consider the unmitigated skeptic's claim that "I know that no one has any knowledge." To say that it is impossible to have knowledge is itself a knowledge claim, and thus this position is self-defeating. Furthermore, this approach is contradicted by our actions, because no one lives this way. 2. Despite the occasional perceptual difficulties we might have, there are good reasons to think that we do have knowledge of the world. While it is true that we can be misled by our senses, it is also true that they give us good information more often than not. 3. Skeptics have raised important considerations about the possibility of having metaphysical knowledge. But their criticisms overstate the case. It is true that getting this kind of knowledge is difficult. But difficult does not mean impossible. 4. Skepticism implies that knowledge requires absolute certainty. However, this expectation sets the bar too high and is unrealistic. If certainty is required, then skepticism has a much stronger case. But if certainty is not required, then skepticism is weak. We might not have an absolute certainty about many things, but this does not mean that we know nothing about them whatsoever.

Explain 3 causes of Skepticism.

1. Philosophers have great concerns with our perceptual limitations. 2. Some philosophers have noted that reason can also lead us astray. 3. Other philosophers have assumed that knowledge requires absolute certainty in order to be counted as knowledge. And because certainty has been so elusive, they suggest that it is impossible to know anything for sure.

Logical/Absolute Certainty

A certainty that is devoid of any sort of doubts or skepticism. The kind of certainty that makes a belief impossible to doubt. For example, religious believers would have no doubts, scientists would never have to alter their theories because they would get things right the first time, and philosophers would be able to solve the great questions about reality with perfect clarity and precision.

Common Sense Skepticism

A natural and healthy form of skepticism that most of us employ on a daily basis. In this version, skeptics question claims that are rightly questionable—like a corrupt politician's promises—but do not subject normal beliefs or commonsense beliefs to continual doubt. In other words, they do not question everyday occurrences, events or basic ideas that are obviously true.

Skepticism

A skeptical attitude; doubt as to the truth of something. The theory that absolute certain knowledge is impossible.

What kind of skeptic was Hume?

Hume was an empiricist. He divided all knowledge claims into two categories: (1) relations of ideas and (2) matters of fact. Knowledge claims based on the relations of ideas are statements whose predicates are already present within the subject.

Sufficient Certainty

In this case, we have very good evidence in favor of a particular belief and we don't know of any significant defeaters for this belief.

What are some reasons why certainty is so elusive?

Certainty can elude is because our senses may fail us, we have a lack of relevant data, or we reason incorrectly. It is also the case that we are finite creatures trying to wrap our minds around things that are complex and difficult. At times, our finite minds are unable to go as far as we would like to go.

What is 1 benefit of philosophical Skepticism?

Common Sense Skepticism allows us to exercise skepticism on a daily basis, and we avoid major problems because of it.

Why is Common Sense Skepticism actually epistemically healthy?

Common Sense Skepticism is considered healthy because it questions claims that are rightly questionable, such as the words of a dirty politician. In other words, they do not question everyday occurrences, events or basic ideas that are obviously true. For these kinds of beliefs and claims, skeptics take them as given and go on living normally.

Contrast and Compare the different forms of Skepticism.

Common Sense Skepticism questions claims that are rightly questionable. In other words, they do not question everyday occurrences, events or basic ideas that are obviously true. For these kinds of beliefs and claims, skeptics take them as given and go on living normally. Rather, our concern is with the different philosophical forms of skepticism that have developed over the last few hundred years. Philosophical versions of skepticism are much more radical in nature. In general, they either reject all knowledge claims about physical and metaphysical things, or they reject knowledge claims about metaphysical things. Most if not all forms of skepticism fall into one of two categories: global skepticism or local skepticism. Global skeptics are skeptical of all knowledge claims of any kind. In other words, they question anyone who claims to know anything about something about a given topic. For global skeptics, it does not matter if a person is making a physical or a metaphysical claim. Their skepticism is applied to all realms of human knowledge. Local skeptics, by contrast, only question knowledge claims of a particular kind—metaphysical claims. Methodological skepticism employs skepticism in its attempt to gain knowledge but is not skeptical in its conclusions. Metaphysical Skepticism suggests that we can have knowledge of the natural world via science and sense perceptions. But it denies the possibility of gaining any knowledge of the metaphysical realm or metaphysical things. Pyrrhonian skepticism is the most radical form of skepticism and is generally what people have in mind when they hear the word skeptic. This view argues that we do not have any knowledge or that we should suspend all judgments about our knowledge due to various factors that make knowledge impossible. This approach is similar to methodological skepticism, because it is skeptical of all knowledge claims, whether physical or metaphysical. But it is unlike the methodological approach in the kinds of conclusions that it draws.

How did Descartes employ Skepticism to arrive at certain knowledge?

Descartes employed systematic doubt about all beliefs to identify those ideas which were undoubtable. Descartes illustrates methodological skepticism. He says, "I thought it necessary to ... reject as absolutely false everything in which I could imagine the slightest doubt and to see, as a result, if anything remained among my beliefs that was completely indubitable. Thus, because our senses sometimes deceive us, I decided to assume that nothing was the way the senses made us imagine it."

Explain Descartes' evil demon hypotheses.

Descartes noted that it is at least within the realm of possibility that an evil demon exists which deceives us about all our perceptions and knowledge claims. If it is possible that this demon exists, then it would seem that we can be certain of nothing whatsoever. Descartes felt that to overcome this concern, one must be willing to explore the possibility to see if there is anything we can know for sure.

Epistemic Humility

Epistemic humility is related to the idea of humility being when someone is not self-promoting or boastful but is applied specifically to the way humility might function in our pursuit of knowledge. This kind of humility seeks to know things but admits what it does not or cannot know.

What did Kant's Skepticism cause him to deny that we could know on the basis of pure reason?

For Kant, knowledge required (1) sense data and (2) an active mind to process, arrange and structure the sense data. But if Kant is right about this, then it would be impossible to gain knowledge with any sense perceptions of a given entity. And because we normally do not have direct access to God via the senses, this would mean that it is impossible to have knowledge of God and the metaphysical realm. Kant went to great lengths to show how it is possible to gain knowledge of the physical realm but argues that metaphysical knowledge is impossible. It caused him to deny metaphysical knowledge.

Global Skepticism

Global Skepticism questions all knowledge claims of any kind. In other words, it questions anyone who claims to know anything about something about a given topic. This skepticism is applied to all realms of human knowledge.

Explain the difference between a global and local skeptic.

Global Skeptics are skeptical of all knowledge claims of any kind. In contrast, Local skeptics only question knowledge claims of a particular kind--metaphysical claims.

Explain the process by which Hume denied the Principle of Causality.

Hume analyzed the idea of causality and said there were three necessary elements to any causal event: contiguity (contact), priority in time (the cause occurs before the event) and a necessary connection between the contact and the event. Hume said we observe only two of these elements: contact and priority. We cannot observe the necessary connection. We naturally assume such a connection, but we do not observe it. The connection is neither a relation of ideas nor a matter of fact. Therefore we cannot claim to know it.

What kind of skeptic was Pyrrho of Ellis?

Pyrrho was a global skeptic who was unwilling to accept any knowledge claim as true.

Pyhrronian Skepticism

Pyrrhonian skepticism is the most radical form of skepticism and is generally what people have in mind when they hear the word skeptic. This view argues that we do not have any knowledge or that we should suspend all judgments about our knowledge due to various factors that make knowledge impossible. (So basically we know nothing for certain.)

Why did Sextus Empiricus adopt Skepticism?

Sextus Empiricus adopted skepticism out of a desire for peace. In his mind, disturbances happen in our lives as we try to determine which view of something is the correct view. And because, according to Sextus, any good argument for something can be opposed by an equally strong counterargument, the seeker of truth will be constantly plagued by doubt and unrest. His solution was to denounce all knowledge claims.

What causes the different variations of certainty?

The degrees of certainty arise from the nature of the objects, entities or issues that we inquire about. In other words, the nature of the thing in question largely determines how it can be known. So, for example, when we are asking about apples, we use our senses to investigate them and see what they are like. By contrast, when we are asking questions about God, who cannot be seen with our eyes or touched with our hands, we must rely on something different. In this, we see how the nature of the object determines how we know it.

Is certainty necessary for knowledge?

The ideal of certainty in knowledge is this: I must accept as true only those claims of which I am rationally certain, having no shadow of doubt. This does not mean that we cannot have certainty about some things. It simply means that most of our beliefs and knowledge claims do not reach this level.

Defeasibility

The property of something - such as a contract, a proposition or an understanding - that can be annulled, invalidated, or similarly "defeated".