The fallacy lies in the conclusion of some logical necessity in the move from that 'affirmation' of a consequent or 'denial' of an antecedent to the exemplified conclusion in either case (Soerfjord 2013, Ph D thesis HKU).Circular reasoning is often of the form: "A is true because B is true; B is true because A is true." Circularity can be difficult to detect if it involves a longer chain of propositions.He wrote about there only being a few kinds of creatures to start with and that these multiplied into many kinds over time.
Carbon dating, like other radiometric dating methods, requires certain assumptions that cannot be scientifically proved.
It is claimed these methods agree with one another.
But closer examination renders them questionable at best.
also known as 'circular logic') is a logical fallacy in which one begins arguing in the wrong end of a premise that indicates some regularity and tries to move either a)in the opposite direction, from an assumption or observation that verifies a consequent, what in medicine is essentially a mere symptom, or, which logically is the same, b)from negating an antecedent, from negating one cause of a symptom that can have many causes, for example in the move from the regularity-premise "if x, then y"; and one ends up 'completing the circle', so to speak (Soerfjord 2013, Ph D thesis HKU).
Version a) has the formal label "Affirming the Consequent", and b) the label "Denying the Antecedent" - both deductively invalid.