Modern logic has Wldergone some remarkable developments in the last hun- dred years. These have contributed to the extraordinary use of formal logic which has become essentially the concern of mathematicians. This has led to attempts to identify logic with formal logic. The claim has even been made that all non-formal reasoning, to the extent that it cannot be formalized, no longer belongs to logic. This conception leads to a genuine impoverishment of logic as well as to a narrow conception of reason. It means that as soon as demonstrative proofs are no longer available reason will no longer...

Modern logic has Wldergone some remarkable developments in the last hun dred years. These have contributed to the extraordinary use of formal logic which has become essentially the concern of mathematicians. This has led to attempts to identify logic with formal logic. The claim has even been made that all non-formal reasoning, to the extent that it cannot be formalized, no longer belongs to logic. This conception leads to a genuine impoverishment of logic as well as to a narrow conception of reason. It means that as soon as demonstrative proofs are no longer available reason will no longer...