(_a_) Is each witness impartial? What is his relation to the subject at issue?

 

(_b_) Is he mentally competent?

 

(_c_) Is he morally credible?

 

(_d_) Is he in a position to know the facts? Is he an eye-witness?

 

(_e_) Is he a willing witness?

 

(_f_) Is his testimony contradicted?

 

(_g_) Is his testimony corroborated?

 

(_h_) Is his testimony contrary to well-known facts or general principles?

 

(_i_) Is it probable?

 

2. _The authorities cited as evidence_

 

(_a_) Is the authority well-recognized as such?

 

(_b_) What constitutes him an authority?