The slogan formalized as a syllogism — and why it fails at premise 4

Syllogism: (1) Extraordinary claims require extraordinary evidence; (2) The claim that a miracle occurred is extraordinary; (3) Therefore any supporting evidence must be extraordinary; (4) No one can clearly define what extraordinary evidence means; (5) Whatever evidence is presented will not qualify; (6) Therefore no one is justified in believing any miracle claim. Mike: premise 4 collapses the whole argument — it is not rigorous thinking, just dismissal.