margin note on logic on page 23 in "Scared Stiff - ..., a Documentary"; page 2 in "Proposition Seven" (Kant called a 'logically valid' structure one that has 'logical truth', the criteria of which he says are as follows:) * 9 Immanuel Kant the physics-, mathand logicprofessor's definition of logical validity (validity: 'strength'), in his lecture notes published 1800 and 1801, is this: logical validity is an argument whose reasons are all possible to be true at the same time ("criterion of possibility: contradiction-rule, the requirement that reasons not contradict one another": consistency) and are sufficient to necessitate one particular conclusion only ("criterion of sufficient reasons: the hanging together of the reasons with what follows", i.e. with the conclusion that follows, causing absurd conflict with the opposite conclusive claim). So logical validity is 1:consistency of all claims involved in the argument and 2:cohesion between reasons and conclusive claim. 1 is verified by a consistency-test, to demonstrate the absence of contradiction, and 2 by a reduction-to-absurdity-test in which we replace the conclusion by the opposite claim and demonstrate a contradiction arising. An argument with reasons (premises) that contradict one another is not logically valid by this standard. It is Immanuel Kant's standard and Ludwig Wittgenstein's standard. Modern statisticians have since invented 'self-contradictionindependent logical validity', but its purpose is selfserving: the purpose being, of course, the benefit: inconspicuous storage of self-contradicting statistical data. The problem with that is that they too must lie to hide some underlying motive, the statistics-limited benefit of it; and they had to create a validity-test that does not work, not quite, because the test (put in the opposite conclusion and verify a contradiction) is not really a 'reduction to' absurdity when the argument tested already has contradicting reasons/ premises in it. Yet they still call it a 'reduction-toabsurdity-test'. An uglier problem is the fact that the prominent proponents for this validity-theory pretend that it is grounded in a naturally occuring phenomenon: {the observation that all valid arguments are self-contradicting after we switch to the opposite conclusive claim} 1 to which "DA!" is all there is to say and proceed to argue that {'therefore, if we come across an argument with contradicting premises, it is valid'} 2 , where { 1+2 } is an argument called 'affirming the consequent', which even they say is 'logically invalid', which it is. So they use a verifiably invalid argument form to argue for the propriety of their theory of validity. It is circular reasoning, so that is why it is invalid. And they make billions in book-sales. The authors who do this are: Paul Tidman, Howard Kahane and Alan Hausman, professors of math and statistics etc., together with their publisher: Wadsworth Cengage Learning, Boston, MA. They have taken over all teaching of 'logic' in all universities on planet Earth. No wonder why de-ductive logic isn't a mandatory bachelor-level course in today's 'higher' education, and I only mention this because I think it ought to be. I hate to sound like some logic-nerd (nerd: 'un-cool person'), but I think it's pretty cool to prove these fraudsters the asses they are. cf. Soerfjord 2013; PhD thesis HKU ksoerfjord@gmail.com