Category Archives: Epistemology

Concept-Checking: Nonrational vs. Irrational vs. Rational

Though this is a relatively rare distinction to be made, it is nonetheless an important one. Nonrationality is NOT the same thing as irrationality. These two terms are different and must be recognized as such. While we are at it, we should discuss what ‘rationality’ actually is…

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An Initial Look into ‘Graham’s Hierarchy of Disagreement’

  1. Name Calling
  2. Ad Hominem
  3. Responding to Tone
  4. Contradiction
  5. Counterargument
  6. Refutation
  7. Refuting the Central Point
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Summary: Einstein vs. Logical Positivism by Rossen Vassilev Jr.

The original article can be found at: https://philosophynow.org/issues/133/Einstein_vs_Logical_Positivism

Vassilev begins his article by pointing out that Logical Positivism was a philosophical movement that originated in the 1920s. Arguably its most critical mission was to establish the same methodology of science and mathematics for other fields, particularly philosophy. The logical positivists dismissed any and all ‘non-scientific’ speculation from genuine analysis or explanation. They insisted that such statements were literally meaningless; only statements that could be logically verified or corroborated through experiment/observation have meaning. This was known as the Principle of Verification (or Verification Principle) and was the driving philosophical and epistemological force behind the Vienna Circle (a particularly influential group of logical positivists).

According to the Principle of Verification, the meaning of any statement lies in its method of verification. Moreover, statements about, say, God or art or ethics would all suddenly be technically meaningless according to the logical positivists. Logical positivists were excited at this prospect because they were very much committed Naturalists. But not all philosophers were on-board with their philosophical approach or its underlying intentions.

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Sentential Logic: Rules of Inference for Deriving Proofs

EXCELLENT RESOURCE AVAILABLE HERE: https://courses.umass.edu/phil110-gmh/text/c05.pdf

Ampersand-In (&I): If one has available lines, A and B, then one is entitled to write down their conjunction, in one order A&B, or the other order B&A.

Ampersand-Out (&O): If one has available a line of the form A&B, then one is entitled to write down either conjunct A or conjunct B.

Wedge-In (∨I): If one has available a line A, then one is entitled to write down the disjunction of A with any formula B, in one order AvB, or the other order BvA.

Wedge-Out (∨O): If one has available a line of the form A∨B, and if one additionally has available a line which is the negation of the first disjunct, ~A, then one is entitled to write down the second disjunct, B. Likewise, if one has available a line of the form A∨B, and if one additionally has available a line which is the negation of the second disjunct, ~B, then one is entitled to write down the first disjunct, A.

Double-Arrow-In (↔I): If one has available a line that is a conditional A→B, and one additionally has available a line that is the converse B→A, then one is entitled to write down either the biconditional A↔B or the biconditional B↔A.

Double-Arrow-Out (↔O): If one has available a line of the form A↔B, then one is entitled to write down both the conditional A→B and its converse B→A.

Arrow-Out (→O): If one has available a line of the form A→B, and if one additionally has available a line which is the antecedent A, then one is entitled to write down the consequent B. Likewise, if one has available a line of the form A→B, and if one additionally has available a line which is the negation of the consequent, ~B, then one is entitled to write down the negation of the antecedent, ~A.

Double Negation (DN): If one has available a line A, then one is entitled to write down the double-negation ~~A. Similarly, if one has available a line of the form ~~A, then one is entitled to write down the formula A.