A discovery of D. Iacksons vanitie. Or A perspective glasse, wherby the admirers of D. Iacksons profound discourses, may see the vanitie and weaknesse of them, in sundry passages, and especially so farre as they tende to the undermining of the doctrine hitherto received. Written by William Twisse, Doctor of Divinitie, as they say, from whom the copie came to the presse