The Post noted Oct. 3 that former White House aide Michael Deaver won permission to use alcoholism as a defense at his perjury trial and that ''at issue is whether alcoholism impaired Deaver's memory.'' It appears to me that, in this ruling, Judge Thomas Penfield Jackson may be playing the classic role of ''enabler'' -- that is, someone who shields the alcoholic from the consequences of his drinking.

Most successfully recovering alcoholics began that recovery when the price they paid for drinking began to outweigh the perceived ''benefits.'' This usually occurs when various well-meaning enablers -- family, friends, employers, the justice system -- no longer protect the alcoholic.

Alcoholism is a costly disease. It destroys families, careers, health and, in Mr. Deaver's case, his memory of certain events. Since it is, however, a disease with a volitional component, an alcoholic does bear the responsibility for his past actions. Finally accepting this responsibility is a major step to recovery.

What is the average, nonfamous, "garden-variety" alcoholic to think when Mr. Deaver is allowed to use alcoholism as a defense? If he can claim he is not responsible because of his alcohol-impaired memory, why cannot someone who is charged with drunk driving plead not responsible ''because I was drunk''? VIRGINIA M. TESORERO Alexandria