Charles Sanders Peirce ( pron.: / ˈ p ɜr s / , [ 8 ] like "purse", September 10, 1839 – April 19, 1914) was an American philosopher , logician , mathematician , and scientist , sometimes known as "the father of pragmatism ". He was educated as a chemist and employed as a scientist for 30 years. Today he is appreciated largely for his contributions to logic, mathematics, philosophy, scientific methodology, and semiotics , and for his founding of pragmatism . In 1934, the philosopher Paul Weiss called Peirce "the most original and versatile of American philosophers and America's greatest logician". [ 9 ] An innovator in mathematics, statistics , philosophy, research methodology, and various sciences, Peirce considered himself, first and foremost, a logician .
Deductive reasoning , also deductive logic or logical deduction or, informally, " top-down " logic , [ 1 ] is the process of reasoning from one or more general statements (premises) to reach a logically certain conclusion. [ 2 ] Deductive reasoning links premises with conclusions . If all premises are true, the terms are clear , and the rules of deductive logic are followed, then the conclusion reached is necessarily true . Deductive reasoning (top-down logic) contrasts with inductive reasoning (bottom-up logic) in the following way: In deductive reasoning, a conclusion is reached from general statements, but in inductive reasoning the conclusion is reached from specific examples.
Logical arguments are usually classified as either 'deductive' or 'inductive'. Deduction : In the process of deduction, you begin with some statements, called 'premises', that are assumed to be true, you then determine what else would have to be true if the premises are true. For example, you can begin by assuming that God exists, and is good, and then determine what would logically follow from such an assumption. You can begin by assuming that if you think, then you must exist, and work from there.