In university they don’t tell you that the greater part of the law is learning to tolerate fools.

The remark wryly punctures the idealized view of legal education as purely intellectual mastery of statutes and doctrine. It suggests that professional competence—especially in law—depends heavily on social endurance: dealing with clients, opposing counsel, bureaucracies, and colleagues whose behavior may be irrational, petty, or self-important. Lessing’s phrasing implies a hidden curriculum: universities teach formal knowledge but often omit the emotional discipline required to function within institutions. The line also carries a broader satirical edge about modern professional life, where success can hinge as much on patience and tact as on brilliance.