Philosophy has developed around the application of logic to various problems in different philosophical fields. Mark Sainsbury notes that philosophical thought is based on inference, with the intent being to develop inferences that are valid. Deductive reasoning is the primary means of accomplishing this, and the basic form of the argument is set:
Typically a piece of reasoning moves from one or more statements which are, at least provisionally, taken for granted to some other statement. The starting-points are called the premisses, the end-point the conclusion. A set of statements consisting of some premisses and a conclusion is called an argument (Sainsbury 63).
The application of philosophical logic invovles an understanding of language or reference.
The relationship between rhetoric and knowledge or truth has been a major issue at least since the time of Plato and has been answered in different ways in different eras. The distinction is often made between approaches seeing the possibility of absolute truth and those seeing the possibility only of probable truth, with each considering how truth of any kind can be expressed rhetorically. Plato presented Socrates in dialogues concerning the issue of how to distinguish true from false rhetoric, and Plato felt that rhetoric as practiced ignored the true knowledge and failed to work toward the good. He saw rhetoric as a means of persuasion rather than a search for the truth. Absolute truth in the Platonic view was known to us before birth, but finding it in this world is very difficult and can be obscured further by false rhetoric (Plato 61-112). The Gorgias of the Platonic dialogue by the same name was a historical figure, a Sophist who believed with them that absolute truth is not possible. He extolled the virtues of language and the power it gave, including the capability of changing the whole person (Plato 40-42).
The relationship between rhetoric and knowled...