Logic: An Empirical Study of A Priori Truths :: Logical Philosophy Philosophical Essays

Logic: An Empirical Study of A Priori Truths ABSTRACT: I distinguish a priori knowledge from a priori truths or statements. A priori knowledge either is evident or is derived from evident premisses by means of correct reasoning. An a priori statement is one that reflects features of the conceptual framework within which it is placed. The statement either describes semantic relations between concepts of the framework or it characterizes the application of the framework to experience and the world. An a priori statement is not necessarily part of anyone’s a priori knowledge. I also distinguish empirical knowledge from empirical statements. Both statements and theories are empirical if they are designed to characterize features of experience and the world. Knowledge is empirical if it fits experience; thus, one must check to see whether it fits. We do not obtain knowledge of logical systems by rational insight of evident truths and careful deductions from evident truths. Adequate logical systems are developed by trial and e rror. Logical knowledge is empirical knowledge that is not generally a priori. It is empirical knowledge of (some) a priori truths and principles of our conceptual systems. Logical systems are empirical theories of these truths and principles. 1. A Priori Knowledge and A Priori Truths In reflecting on our knowledge of logic, I was puzzled because logical knowledge seems to have incompatible characteristics. This knowledge has some claim to a priori status, but logical systems are also developed and "tried out" to capture linguistic practice. Can an a priori body of knowledge have an empirical character? To answer this, we must consider what it is to be a priori. A priori knowledge has traditionally been conceived to be the product of insight and reasoning. Some truths are simply evident to someone who understands them and reflects on them. These truths are known to be such without being checked in experience. Other a priori knowledge is inferred by evidently correct reasoning (this is deductively correct reasoning) which begins from a priori knowledge. That a priori knowledge which is not evident must be obtained by chains of reasoning which ultimately begin with evident premisses. A priori knowledge is the knowledge which Hume claimed to be "either intuitively or demonstratively certain." (An Inquiry Concerning Human Understanding) It isn’t clear what there is about the objects of a priori knowledge that makes a priori knowledge possible. If we have a faculty of rational insight, on what does it "operate"?