Rationalism and Skeptisism

Skepticism

Philosophical position that we don’t have knowledge.

Universal skeptics

Deny we have any knowledge at all.

Limited skeptics

Believe we have some knowledge. Only doubt that we can have knowledge in certain areas. Ex. confident in scientific knowledge but not moral knowledge

Pyrrho

360-270 BCE Most influential ancient skeptic. Left no writing so knowledge of him comes from followers.

Pyrrhonian Skepticism

Pointed out that we don’t know whether our sense experience corresponds to reality. Made opposing arguments of equal strength on any issue. If the pro argument was the same strength as the con, then reasonable action is to withhold judgment as to the truth of the matter.

We should withhold belief on all matters. Should follow laws, moral traditions, and religious customs of the city we live in but be careful not to believe that any of these things are true. We make claims about how the world appears to us but not how it really is.

Rene Descartes

1596-1650: Famous mathematician and philosopher during the early modern period. Wanted to have the same certainty in his knowledge of science and philosophy that he experienced in mathematics. Not a skeptic, but used skeptical methods to pursue certain knowledge. Wants indubitable knowledge. Beleived if you really know soemthing, it is impossible for you to doubt it.

House Analogy

Compares a person’s beliefs to the structure of a house. If the foundation is not sound, the structure depending on the foundation will be faulty. If the most fundamental principal beliefs are not sound, the conclusions drawn from them cannot yield knowledge.

Methodological Doubt

Descartes used it as an instrument. Test beliefs to see if they can be doubted. A belief that may be doubted may not be treated as knowledge. Clear away old foundations by setting aside beliefs that can be doubted. Tests principles instead of particulars. If principles are doubted, then many particulars based on them are doubted as well.

Reasons to Doubt

1.Me senses sometimes deceive me in situations where senses don’t provide adequate. (Will not doubt all the time) 2. I might be dreaming. How does he know he’s not dreaming now. 3. There might be an evil deceiver. Doesn’t have to be likely only possible. All powerful being created us where we believe false to be true.

Simple sensations

Are perceptions like shape and color.

Complex sensations.

Like a painting. May be fictional but stuff in it like animals (simple sensations) are real.

Universal Belief Falsifier.

Like an evil deceiver. 1. Theoretically possible state of affairs. 2. No way of knowing if it is actual or not. 3. If true, can't distinguish beliefs that are true from beliefs that seem to be true but are not.

Cannot Doubt

Descartes cannot doubt he exists. I think therefore I am. Can’t doubt existence as a thinking thing. Everything else is put into doubt.

Empirical Belief

Beliefs that form from the use of senses.

Local Doubts

Doubts about a particular sense experience or some other occurrence at some point in time.

Global Doubts

Ex. What if world was made 5 min ago. Doubt everything

a priori knowledge

Knowledge justified independently of experience.

posteriori knowledge

Knowledge gained from experience or senses.

Fundamental truths are

Either innate or self evident.

Innate ideas

Are ideas or principles that the mind already contains prior to experience. Not aware of these ideas until cognitively mature. Different from instince.

Self evident

Not all rationalists believe in innate ideas. Instead, the mind has innate structures that lead it to think in certain ways. The mind has a natural predisposition to recognize truth.

Innate vs self evident.

mind being aware vs mind containing ideas known to be true.

Plato

Precursor of rationalist tradition

Meno’s Challenge

How will you look for something if you don’t know what it is? Can’t find the answer unless you recognize it. Can’t recognize answers unless you already know them. Learning seems impossible.

Socrates gave a slave a math problem, and he eventually solved it. Plato said two sticks can be similar, but we know they are not equal. Know this through innate ideas.

Forms.

We collect knowledge in forms like Form of Equality. Perfect unchanging reality.