Severity apes wisdom. It looks as wisdom looks, it acts as wisdom acts. But severity is no more a kind of wisdom than fool's gold is a kind of gold. Severity is to wisdom as pedantry is to intelligence. Any quality of mind or dedication of energies that can achieve intelligence can also incur pedantry. Whoever ends up a pedant has missed becoming intelligent, and whoever ends up intelligent has evaded being a pedant. The same terms holds between whoever ends up severe and whoever ends up wise.
Being a pedant is easier than being intelligent. To continue being a pedant only means repeating what you have done before. To continue being intelligent means judging what you have done before. Severity, in the same way, is easier than wisdom. To continue being severe only requires that you go on denying and refusing. To continue being wise requires that you sometimes deny and sometimes accept, sometimes refuse and sometimes permit, according to the good you can do.
Sometimes you must be severe to be wise. Often you must be severe with yourself, must brace or flense yourself. Rarely you must be severe with others, to awaken or correct them. Severity taints trust (no one hugs a cactus twice): the difference between often and rarely is in the impossibility of resenting your own severity, and the certainty of your severity being resented by others. They will resent your severity even when you owe it to—even when they ask it of you. Sometimes you must be severe to be wise; but the wisdom is in the wisdom, not in the severity.