Propositional Knowledge, Truth, Reality, and the Limits of Understanding
Propositional Knowledge
A proposition is a declarative sentence that affirms or denies something. There are two types:
- Empirical propositions: Assert or deny something about the world, have content, and can be contrasted with experience.
- Formal propositions: Do not have empirical content. They say nothing about the world but rather about the relations between symbols.
For a proposition to contribute to knowledge, it has to be true and justifiable.
Truth and Reality
Truth has been one of the fundamental problems of theoretical philosophy. Facts are true or authentic; we also believe that propositions can be true or real.
Truth of Facts
The distinction between reality and appearance has always been subject to much controversy. However, appearances hide from reality. Appearances deceive us. Truth is identified with authentic reality, in opposition to apparent reality. That is to say, true facts are authentic facts in contrast to apparent or misleading ones. The search for truth is a process of unveiling authenticity.
Truth of Propositions (Types of Reality)
To see the statements about them, truth would be attributed not only to reality, especially propositions. There are different classes:
Truth as Correspondence: Matching the proposition and reality. The first to propose this theory was Aristotle. This theory is intuitive; it fails to determine the correspondence between language and reality.
Truth as Coherence: A true proposition does not contradict the rest of the accepted propositions. The first philosopher to propose this was Friedrich Hegel (1770-1831). According to Hegel, the truth of a proposition is not determined by its application to reality but by its coherence with the rest of the propositions of the theory.
Truth as Success: A proposition is true when it leads to success. The truth or falsehood of a proposition agrees with the consequences. A proposition is true if, when put into practice, it proves successful; instead, a false proposition has negative consequences.
Truth of Formal Propositions: Propositions say nothing about reality; their truth cannot consist in correspondence with it or the utility of application. Truth is like consistency. A proposition can be true if it does not contradict the rest of the accepted propositions.
The Limits of Knowledge
Is there a limit? To what extent can we be sure that we acquire knowledge?
The Possibility of Knowledge
Dogmatism: Asserts that secure and universal knowledge is possible and that we can be absolutely sure of it. It defends the possibility of extending our knowledge. Descartes, using reason and a good method, believed he could provide valid and universal knowledge.
Skepticism: Opposed to dogmatism, moderate skepticism doubts firm and sure knowledge, while radical skepticism denies that knowledge is possible. Skeptics consider that access to strong and secure knowledge is an unattainable desire. While for some skeptics, “knowing” guides our lives, for others, it is rejected due to its unfulfilled nature. Pyrrho (360-270 BCE) was considered the first skeptic. Feelings are changing; they do not provide firm and sure knowledge.
Criticism: An intermediate position between dogmatism and skepticism. Kant was a critical thinker. Knowledge is possible; it is unquestionable and final but should be reviewed and criticized.
Relativism: Denies the existence of absolute truth, valid at any time and place. It rejects universal and objective knowledge and considers that there are only individual opinions, valid in a particular social context, culture, and history (universal truths cannot be achieved, only relative ones).
Perspectivism: Shares many aspects with relativism but differs in that it does not negate the possibility of absolute truth. It offers a partial view of reality. This vision is not false; it is irreplaceable. All perspectives are true, and the reunion of all of them is the absolute truth.
Scientific Explanations
The concept of knowledge is a description of reality and an explanation of why what happens occurs. A scientific explanation is, therefore, the “answer to a why.” To be scientific, it must be understandable and illuminating. Ernest Nagel classified scientific explanations into four types:
Deductive: Taps into general laws. Investigations show that the conclusion is reached logically. Examples: life sciences, physics, and formal sciences. Why has the apple tree fallen?
Probabilistic: Why has Peter caught the flu? Certainty is never reached to establish factors deductively.
Teleological: Why did they declare war on Iraq in 2003? Taps into the intent or purpose that leads to an action. It sheds light on historical facts or general human behaviors.
Genetic: Goes back to the origin or history of a phenomenon in question. Examples: history, natural sciences. Why are animals and plants incorporated by eukaryotic cells?