1.1.3"Knows," "reasonably believes," "reasonably should know": the ladder (Rule 1.0(f), (h), (i), (j))

Rule 8.1 turns on what the lawyer knows; other rules turn on what she reasonably believes, or should have worked out. Rule 1.0 defines each rung, and the exam's answer often sits in the gap between two.

Rule 1.0(f) — knows. "'Knowingly,' 'known,' or 'knows' denotes actual knowledge of the fact in question. A person's knowledge may be inferred from circumstances." The top rung. Rule 3.3(a)(3)'s duty to remedy false evidence needs it: a lawyer who only suspects a witness lied has no remedial duty yet, though knowledge can be inferred from what she saw.

Rule 1.0(i) — reasonably believes. "'Reasonable belief' or 'reasonably believes' when used in reference to a lawyer denotes that the lawyer believes the matter in question and that the circumstances are such that the belief is reasonable." Two parts, one inside the lawyer's head and one outside it. Rule 1.6(b)(1) lets a lawyer reveal information to prevent reasonably certain death if she reasonably believes disclosure necessary: an honest belief the facts cannot support fails, and so does a reasonable case she does not herself believe.

Rule 1.0(j) — reasonably should know. "'Reasonably should know' when used in reference to a lawyer denotes that a lawyer of reasonable prudence and competence would ascertain the matter in question." The bottom rung, the only one that catches a lawyer who never found out. Rule 4.4(b)'s duty to notify the sender of a misdirected document applies when the lawyer knows or reasonably should know it was sent by mistake.

Rule 1.0(h) — reasonable. "'Reasonable' or 'reasonably' when used in relation to conduct by a lawyer denotes the conduct of a reasonably prudent and competent lawyer." The yardstick on every rung below the top.