However, to argue that our nature or constitution forces us to abide by the laws of logic is no longer a logical justification; it is to incorrectly shift from logical to psychological or biological considerations (1893, XVI-XVII).
Second, pure general logic is absolutely binding on any rational human thinker and provides an unconditional logical ought: the laws of logic are the categorically normative laws of thought for all actual and possible rational animals.
Further, Quine argued that empirical hypotheses can't logically imply anything about experience except against a background of assumed laws of logic.
Directed at 10-year-olds, the book uses classroom dramas to teach the laws of logic.
But party defections don't obey the laws of logic; they are subjective traumas reflecting human dilemmas.
They don't use the word "miracle" for nothing – they know their faith defies laws of logic and nature.
In a demonstration (or proof), for example, the connection between any premise and the conclusion is mediated by other premises and by the laws of logic.
He wanted to believe that true omnipotence meant God could transcend the laws of logic - whereas his wife, another priest, and his boss the Archbishop apparently disagree.
If metaphysical arguments suggested that fundamental laws of logic such as the principle of noncontradiction that a statement and its contradictory cannot both be true might not be in order, the only conclusion to draw was that such arguments must be confused: without observation of the laws of logic there could be no coherent thinking of any sort.
The former proviso reflects the view that the laws of logic and mathematics cannot be false; the latter embodies the idea that any statement whose truth or falsity is not determined by the laws of logic and mathematics might turn out to be true (or false).
Philosophers like Derek Parfit use logic in their quest for moral truth, but it was Aristotle, the original formulator of the laws of logic, who first pointed out logic's limitations ("How to Be Good," by Larissa MacFarquhar, September 5th).
